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Global Twborculoili Programs*
WORLD H1ALTH ORGANIZATION
20, Avonuo Appla
CH - 12 11 GINIVA 27
SWITZERLAND
Telephone 41 22 791 2963
Faciimile 41 22 791 4199
1
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or t^eMANABEMENT
WHO/TB/96.210 (Rev.1)
Distr.: General
Original: English
GUIDELINES FOR
THE MANAGEMENT OF
DRUG-RESISTANT
TUBERCULOSIS
by
Sir John CROFTON
Professor Emeritus of Respiratory Diseases and Tuberculosis
University of Edinburgh, Scotland
Pierre CHAULETand Dermot MAHER
Global Tuberculosis Programme
World Health Organization, Geneva, Switzerland
with contributions from
Jacques GROSSET
William HARRIS
Norman HORNE
Michael ISEMAN
Bryan WATT
o
J
I
© World Health Organization
1997
,•
CONTENTS
1
FOREWORD
5
INTRODUCTION
7
1.1
1.2
1.3
1.4
2
13
2.1
2.2
13
13
13
13
14
2.4
2.5
2.6
2.7
2.8
14
14
14
17
3.1
17
18
Some provisos...........................................................
Collecting carefully the data concerning the patient
Considering the criteria of failure of the
retreatment regimen .................................................
Interpreting the data for an individual patient .........
20
21
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
23
4.1
4.2
4.3
4.4
23
3.4
4
Specialized unit ................................................................
Designing an appropriate regimen .................................
Reliable susceptibility testing...........................................
Reliable drug supplies .....................................................
Priority is prevention.........................................................
Using WHO standardized regimens for new cases
and retreatment................................................................
MDR tuberculosis as a consequence of poor treatment
Long-term involvement of staff and financial resources
ASSESSING THE INDIVIDUAL CASE
OF APPARENT MDR TUBERCULOSIS
3.2
3.3
?
.7
.8
.9
11
BASIC PRINCIPLES FOR MANAGEMENT OF
MDR TUBERCULOSIS
2.3
3
Definitions..............................................................................
How is multidrug resistant (MDR) tuberculosis produced?
Magnitude of the problem
.
How to prevent MDR tuberculosis? ...................................
Essential antituberculosis drugs...............
Second-line antituberculosis drugs...........
Cross-resistance.........................................
Classification of antituberculosis drugs for
treatment of MDR tuberculosis.................
24
25
26
3
CONTENTS
FOREWORD
5
31
5.1
5.2
5.2.1
5.2.2
6
THE PLACE OF SURGERY
6.1
6.2
6.3
ANNEX
Basic principles
Examples of acceptable regimens in
programme conditions
If susceptibility test results are not available
If susceptibility test results are available
Indication for surgery
Timing of surgery.........................
Antituberculosis chemotherapy after surgery
SECOND-LINE ANTITUBERCULOSIS DRUGS
references
1 About one third of the world's population is infected by M. tuberculosis.
Worldwide in 1995 there were about nine million new cases of
tuberculosis with three million deaths. M. tuberculosis kills more
people than any other single infectious agent. Deaths from
tuberculosis comprise 25% of all avoidable deaths in developing
countries. 95% of tuberculosis cases and 98% of tuberculosis
deaths are in developing countries; 75% of these cases are in the
economically productive age group (15-50 years).
31
32
32
33
2 As a consequence, the world is facing a much more serious
situation as we approach the twenty-first century than in the mid1950s. Due to demographic factors, socio-economic trends,
neglected tuberculosis control in many countries, and in addition,
the HIV epidemic, there are many more smear-positive pulmonary
tuberculosis cases, often undiagnosed and/or untreated. When
tuberculosis cases are treated, poor drug prescription and poor case
management are creating more tuberculosis patients excreting
resistant tubercle bacilli.
37
37
37
37
3 In 1991, the World Health Assembly adopted Resolution WHO 44.8,
recognizing “effective case management as the central intervention
for tuberculosis control”, and recommending the strengthening of
national tuberculosis programmes by introducing short course
chemotherapy and improving the treatment management system.
Since 1992, the WHO Global Tuberculosis Programme has
developed a new strategy, to meet the needs of global tuberculosis
control.
39
45
Tuberculosis control requires effective, inexpensive, simple and
largely standardized technology, and the managerial skills to
implement them as a large scale intervention in each country.
4 The success of the WHO case management intervention or “DOTS
strategy" depends on the implementation of a policy package with 5
components:
• government commitment;
• case detection by microscopy through predominantly passive
case finding in existing primary health care (PHO) services;
• Directly Qbserved Treatment, Short-course chemotherapy:
standardized short-course chemotherapy regimens administered
under close control, given free of charge, for smear-positive new
and retreatment cases;
• regular drug supply of all essential antituberculosis drugs;
• establishment and maintenance of monitoring mechanisms of
case detection and treatment outcomes, based on recording
individual patient information in district registers and a system of
quarterly reporting.
4 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
J.
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5
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FOREWORD
INTRODUCTION
(■£)
5 In all countries that have adopted the “DOTS strategy" under
1.1
programme conditions the cure rates (and the success rates for th
le
Veatment of smear-positive tubercuiosis cases ar
When this strategy is implemented over a long period for the
tandardized treatment of smear-positive tuberculosis cases there will
be a huge reduction in sources of infection and in transmSon
DEFINITIONS
a Drug-resistant tuberculosis. This is a case of tuberculosis (usually
pulmonary) excreting bacilli resistant to one or more antituberculosis
drugs.
For the future, the top priority remains to administer standardized short
course chemotherapy regimens to all smear-positive cases (new and
dmos a^rt"1 CaSeS-’ThiS PriOrity reqUi'eS ,he maxmm °f effort time
In patients who have not had prior treatment with antituberculosis drugs,
the bacterial resistance is called primary resistance (if it is certain that
the patient has not had previous treatment). After clinical assessment, if
it is doubtful that the patient really has not received prior treatment, this
is called initial resistance. Initial resistance is a mixture of primary
resistance and undisclosed acquired resistance.
In patients with some record of previous treatment, the bacterial
resistance is called acquired resistance.'
retreatment regimen should be considered. Although these cases
In new patients, the WHO standard first-line regimens (6 months or 8
months) overcome the risk of failure due to primary resistance.
In the majority of previously treated patients (more than one month), the
WHO standard retreatment regimen (8 months) reduces the risk of
failure due to acquired resistance.
L^TcJssed
COntr°' W°rkShOp held in
b Failure of retreatment. The definition of failure of the WHO retreatment
regimen is a tuberculosis patient excreting bacilli either after 5 months of
chemotherapy given under direct observation by a health worker or after
completion of the fully supervised 8-month retreatment regimen, m
October
This retreatment regimen consists of three drugs throughout (isoniazid,
rifampicin, ethambutol) supplemented by pyrazinamide during the first 3
months and streptomycin during the first 2 months. The conventional
abbreviation for this regimen is 2SHRZE/1HRZE/5HRE. If it is properly
administered to the patient, any bacilli remaining after 5 months
(or more) of chemotherapy are usually resistant to at least one or two of
the main bactericidal drugs given (isoniazid and/or rifampicin).
rije WHO Global Tuberculosis Programme has prepared these
c Chronic case. A chronic case is now defined by the failure of a fully
supervised WHO retreatment regimen, (t) A chronic case has received
at least 2 courses of chemotherapy, and sometimes more than two
courses (complete or incomplete). Chronic cases are usually, but not
always, excretors of resistant bacilli (the rate of acquired resistance is
very high in this category of patients) and often excretors of MDR bacilli.
6 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
JJ
7
Occasionally, with single-drug treatment or inappropriate drug combinations, resistance can occur after
only two or three weeks. It may be necessary to consider this when prescribing drug combinations for an
individual patient.
7
a
a
INTRODUCTION
INTRODUCTION
d iTfnZXTnd?? MDR tubZrCUlosis- MDR bacilliare distant to at least
son azid and rifampicin, the main antituberculosis drugs. MDR is the
most severe form of bacterial resistance today. Il is why MDR
wunki'eTrz^ 30 ,mP°rtant concern for tuberculosis control in many
b frequent or prolonged shortages of antituberculosis drugs (due to poor
management and/or financial constraints in developing countries);
c use of drugs (or drug combinations) of unproven bioavailability.
re^rtedVd-ff
SeVera' ou,breaks MDR tuberculosis have been
reported in different regions of the world, as a consequence of
inappropriate use of essential antituberculosis drugs. Usually MDR
tuberculosis occurs in chronic cases, after failure of WHO or other
retreatment regimens and represents a significant proportion of
°S,S -PatunlS W,th ac<’uired resistance. Exceptionally, MDR
The following also have the effect of multiplying the risk of successive monotherapies and
selection of resistant bacilli:
a the patient's lack of knowledge (due to a lack of information or due to
inadequate explanation before starting treatment);
b poor case-management (when the treatment is not directly observed,
especially during the initial phase).
aken amkuhArr
CaSeS’ Le-in patients who have never
taken antituberculosis drugs, and who have been infected by MDR bacilli
In most settings, these new cases with MDR bacilli represent a very
small proportion of new tuberculosis patients with primary resistance
1.3
1.2
HOW IS MDR TUBERCULOSIS PRODUCED?
the Pha"°men°n
mammade.6' 'OrmS
(4.5)
• prescription of chemotherapy
• management of drug supply
• case management
• process of drug delivery to the patient.
3
nhLTo
resista"' bacilli are the
°f !nadec’uate chemotherapy to the multibacillary
tUpercu'os,s cases (e-Q- only 2 or 3 drugs during the initial
Sant ‘"id";3 n6W Smear-p0Si,iVe pa,ienl with bac™ «a"y
b the addition of one extra drug in the case of failure, and repeating the
To monotherapy
(6. 7. 8. 9. 10. 11)
In programme conditions, there are two groups of bacteriologically positive (smear and/or
culture) tuberculosis patients:
MDR tuberculosis is entirely
Drug resistant bacilli are the consequence of human error in any of the following:
tolo^ng'C0mm0n mediCal errOrS leadin9 t0 the selection
MAGNITUDE OF THE PROBLEM
Wha‘ am°Un,S
• New cases, i.e. patients who have never taken antituberculosis drugs
(or for less than 1 month).
• Old cases, i.e. patients previously treated with antituberculosis drugs
during one or more courses of chemotherapy, whether or not completed.
During the early stages of implementation of a national tuberculosis control programme,
old cases (previously treated by usually inappropriate and non-standardized chemotherapy
regimens) may represent up to half of notified cases. In this situation, acquired resistance
emerges as a priority problem, as the rate of acquired resistance is 50% to 80% in
previously treated cases. The priority solution is to standardize at country level and to
adopt the WHO recommended standard regimens of chemotherapy for new cases and for
retreatment cases, in order to stop the creation of more cases with bacterial resistance.
Even if the proportion of MDR tuberculosis among drug resistant tuberculosis is high, the
top priority is not the management, but the prevention, of MDR tuberculosis.
Experience from a number of successful national control programmes assisted by WHO or
IUATLD suggests that, when a national tuberculosis control programme has been well
implemented for several years, the proportion of "old cases" decreases and represents
10%-20% of all pulmonary tuberculosis cases. The rate of acquired resistance is around
20% among "old cases" (previously treated patients), in whom the rate of MDR
tuberculosis is 4%-10%. w
The most common errors obsenred in the management of drug supply are the following;
3 thLdS71eXpfer!eTd by poor patients in oblaining all the drugs that
ey need (due to lack of financial resources or social insurance);
8 guidelines for the management of drug-resistant tuberculosis
Whatever the stage of implementation of a national tuberculosis control programme, the
occurrence of bacterial resistance in new patients (never previously treated), or primary
resistance, is a consequence of the level of acquired resistance in the community.
9
i
n
n
INTRODUCTION
JeXntfoe hioh^m °'
'S Wh°
eXCre‘OrS °'resistant bacilli <“"9
after
L ..Sh ? pTary rTtanCe in new patien,s is ,ower than the rate of
inXdn? inC0, The rate Of primary resistance is usually 5% or less
n good national programmes, and 15% or more in new programmes
chemotherapyafter *
°f Unor9anized and chaotic tuberculosis
INTRODUCTION
1.4
HOW TO PREVENT MDR TUBERCULOSIS?
1.4.1
In new cases
(12- ’3}
The best prevention is to give each new case of sputum-positive pulmonary tuberculosis
an effective regimen of short course chemotherapy (6 months or 8 months) with four drugs
(isoniazid, rifampicin, pyrazinamide and ethambutol or streptomycin) during at least the first
2 months, given under direct observation.
b Primary resistance is less severe than acquired resistance:
* than ^eS?anC^ 'S m°re Often tO one drug (streptomycin or isoniazid)
than to two drugs (usually streptomycin plus isoniazid). Primary
resistance to three drugs and primary multidrug resistance are
rirnnf,Ona' By co?trastl acciuired resistance usually concerns two
drugs or more, and multidrug resistance is relatively frequent.
* InHh’nr6’ ?•rasistance ('•e- minimum inhibitory concentration of
antibiotics) is lower in primary than in acquired resistance.
!S *hy primary ^stance hardly affects the outcome of treatment with a WHO
posXe
standardpal^s
regimen
0C
combining
°mb,n,ng f0ur
four drugs in the
thi initial phase of treatment in new smear-
In patents previously treated with one course of chemotherapy, the WHO standard
WHO recommended regimens are as effective in patients with bacilli initially resistant to
isoniazid and/or streptomycin as in patients with susceptible bacilli. The cumulative rate of
failure and relapses after 3 years is from 0%-4% in new cases, 0-3% in patients with
initially susceptible bacilli and 0-13% in patients with primary resistance.
Theoretically, infection with MDR bacilli will be the cause of failure of very few individuals to
respond to the initial regimen. Failure to respond because of infection with MDR bacilli
represents an exceptional situation. Even when transmission of MDR bacilli from an "old"
patient to a new patient is clearly demonstrated, it has still not been documented that
primary MDR contributes significantly to the treatment failure rate of WHO standard
regimens for new cases in programme conditions.
1.4.2
In old cases
In the group of tuberculosis patients previously treated with one or several courses of
chemotherapy and who remain sputum positive (by smear and/or culture), three
subpopulations can be observed:
• patients excreting bacilli still susceptible to all antituberculosis drugs;
• patients excreting bacilli resistant to at least isoniazid, but still
susceptible to rifampicin;
• patients excreting bacilli resistant to at least, isoniazid and rifampicin.
The respective proportion of the three subpopulations varies according to the
chemotherapy applied in the community during the past years. It varies also with the
number of courses of chemotherapy received by the patients, rw;
a In patients who have failed after the first course of chemotherapy
(WHO recommended regimens or any other), the proportion of patients
excreting bacilli still susceptible to all drugs is usually higher than the
proportion of the two other subpopulations. For this reason, the standard
WHO retreatment regimen of 8 months (using 5 drugs for the first 2
months, then 4 drugs for the third month, and then 3 drugs for the
remaining 5 months of treatment, i.e. 2SHRZE/1HRZE/5HRE) given
1 0 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
11
n
INTRODUCTION
^BASIC PRINCIPLES FOR MANAGEMENT
OF MDR TUBERCULOSIS
under direct observation, can cure the majority of patients: those having
still susceptible bacilli, and those having bacilli resistant to isoniazid
and/or streptomycin, but still susceptible to rifampicin.
b In patients who have failed after two courses of chemotherapy (the
second being the fully supervised standard WHO retreatment regimen),
the proportion of patients excreting resistant bacilli is the majority (up to
80%). The proportion of patients with MDR tuberculosis can be as much
as 50% of this group of patients with bacterial resistance. For this
is Hkelyto fa?0^ aPPliCat'On °f the standard WH0 retreatment regimen
2.1
SPECIALIZED UNIT
Treatment of patients with MDR tuberculosis (especially those with resistance to rifampicin
and isoniazid) may have to involve “second line” reserve drugs. These are drugs other
than the “standard" essential antituberculosis drugs, i.e. rifampicin (R), isoniazid (H),
streptomycin (S), ethambutol (E), pyrazinamide (Z), thioacetazone (T). These reserve
drugs are much more expensive, less effective and have many more side effects than
standard drugs. They should only be made available to a specialized unit and not in the
free market. It Is the responsibility of national health authorities to establish strong
pharmaceutical regulations to limit the use of second-line reserve drugs in order to
prevent the emergence of incurable tuberculosis.
2.2
DESIGNING AN APPROPRIATE REGIMEN
Designing an appropriate regimen for the individual patient needs experience and skill.
It includes allocating the time and patience to define precisely the following:
a which regimen(s) the patient had previously received;
b whether the patient took all the drugs in each regimen prescribed and for
how long;
c to find out what happened bacteriolpgically, in terms of sputum positivity
(at least by direct smear, if possible also by culture and susceptibility
tests) during and after the administration of each regimen. Clinical and
radiological progress or deterioration is much less reliable but may be
used as a check on the bacteriological results.
2.3
RELIABLE SUSCEPTIBILITY TESTING
The specialized unit must have the services of a laboratory able to carry out culture and
reliable tests for drug resistance (to the essential drugs and also to second-line drugs).
The quality of the susceptibility tests carried out in this laboratory should be regularly
checked by another reference laboratory at national or supranational level.
2.4
RELIABLE DRUG SUPPLIES
The unit must also be guaranteed reliable supplies of the expensive “second line" reserve
drugs, so as to ensure that any treatment undertaken for an individual patient can be
successfully completed.
1 e2 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
13
BASIC PRINCIPLES FOR MANAGEMENT
LfJ OF MDR TUBERCULOSIS
(ft)
2.5
PRIORITY IS PREVENTION
A country with limited resources may reasonably decide that its resources should be
concentrated on ensuring that all new patients complete the standard national treatment
and are thereby cured. With good standard treatment meticulously prescribed and
meticulously administered, multidrug resistance should not occur.
The proper assumption is that the emergence of MDR tuberculosis Is always due to
medical error: prescribing an unreliable regimen, using unreliable drugs, or failing to
ensure (by directly observed treatment and education of the patient and his family) that the
patient takes the drugs as prescribed and for the full period prescribed. MDR tuberculosis
should always be regarded as a result of a failure of effective implementation of the
national programme. Top priority should be given to preventing such failure.
2.6
■MB BASIC PRINCIPLES FOR MANAGEMENT
LA J OF MDR TUBERCULOSIS
of WHO recommended standardized treatment regimens (for new and retreatment cases).
If such a unit is set up (or perhaps more than one in a very large country) a gross waste of
resources will occur unless it is run by skilled and experienced specialists who are given
ongoing long-term responsibility for it, and who work closely with a reference laboratory
able to carry out reliable tests for drug resistance. It must be provided with the resources
outlined above. An inadequately resourced unit can do more harm than good. It may
perpetuate and spread MDR tuberculosis, with the result that tuberculosis patients and
health workers lose confidence in the treatment.
USING WHO STANDARD REGIMENS FOR NEW CASES
AND RETREATMENT
The following patients should be given the WHO retreatment regimen (ir. patients with
treatment failure after the standard national regimen; relapses; patients returning after
premature interruption of treatment. The vast majority will be cured with this retreatment
regimen. Most failures are due to the use of an incorrect regimen and/or failure to ensure
that the regimen is fully administered and directly observed.
Very rarely failure may be due to initial resistance to three or more of the five drugs used in
the retreatment regimen (owing to gross errors in previous therapy for that patient).
2.7
MDR TUBERCULOSIS AS A CONSEQUENCE OF POOR
TREATMENT
In some countries MDR tuberculosis has arisen from poor treatment before the introduction
of the National Programme or because some patients received poor treatment outside the
National Programme (from private qualified, or even unqualified, practitioners). As a wide
variety of different poor regimens may have been used for such patients, the MDR
'■ tuberculosis cases which arise will require detailed assessment by the specialized unit.
2.8
LONG-TERM INVOLVEMENT OF STAFF AND FINANCIAL
RESOURCES
With these considerations in mind, a specialized unit for dealing with MDR tuberculosis
may reasonably be regarded as an expensive luxury which Is only affordable where
national resources are moderate or good, and after full implementation at country level
1 4 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
15
0____________
ASSESSING THE INDIVIDUAL CASE
OF APPARENT MDR TUBERCULOSIS
The suspicion of MDR tuberculosis occurs in two situations:
a when you receive a report from a laboratory indicating at least “strains
resistant to isoniazid and rifampicin";
b when you observe in a smear-positive patient no response to the
standard WHO retreatment regimen.
3.1
SOME PROVISOS
a Apparent MDR strains reported by a local laboratory should not be taken
uncritically at face value. Errors occur in laboratories as elsewhere.
Some laboratories are less reliable than others. The specimen may have
been mislabelled or have come from another patient. If the result is a
single one, and if it does not accord with clinical data (see below), repeat
at least one, and preferably two tests.
b If there is no response to the standard WHO retreatment regimen,
remember that many apparent treatment failures are due to the patient
having failed to take his treatment and not due to MDR bacilli. Such
patients should respond to the fully supervised standard WHO
retreatment regimen.
c Explain to the patient how essential it is to know exact details of his
previous treatment. If you are going to be able to cure this patient, you
must know exactly what and how much of the prescribed treatment the
patient actually took. The patient may not be able to admit that failure is
the patient s own fault, so also question the family in the same way, and
in the patient’s absence. Also check with the patient’s previous records
and previous medical advisors.
d Just because there is a standard national regimen, do not assume that
the patient has necessarily received it. Check with the records, the
patient, the patient’s family, the patient’s previous doctors. There may
well have been errors. In some cases the patient may have received
other and unreliable treatment from a private practitioner, an unqualified
person or even, in some countries, from a shopkeeper. From your
knowledge of local conditions you can judge how likely this is. But even
if you think it unlikely you should enquire. Enquire also whether the
patient has been given the doctor’s advice or prescription in writing. If so
make careful notes from these documents of the dose of each drug, its
frequency of administration, the accompanying drugs, and the dates
when each drug was started and stopped.
17
ASSESSING THE INDIVIDUAL CASE
1 OF APPARENT MDR TUBERCULOSIS
3.2
COLLECTING CAREFULLY THE DATA
CONCERNING THE PATIENT
ASSESSING THE INDIVIDUAL CASE
1 OF APPARENT MDR TUBERCULOSIS
Table P
Collecting data for a patient with suspected MDR
Patient’s name .
Age
Sex
Address
.
Use a table based on Table 1 to tabulate information in a series of vertical columns.
Column 1
Date column. Date of diagnosis followed by dates of starting and
completing regimens with exact doses and frequency of all the drugs
taken. Enter subsequent data opposite the relevant date in this column.
i
Dates and chemotherapy
Column 2
Tabulate opposite the relevant dates sputum direct smear results.
a Date of diagnosis:
Column 3
Ditto for culture results (if available).
b Date of starting first course of
chemotherapy:
Column 4
Ditto for each resistance test (if available). Do this for each drug which
the patient has received (plus, if available, results for drugs which the
patient has not received). If your laboratory is a reliable one, regard any
degree of drug resistance reported as likely to be of clinical significance
provided it is consistent with the patient's treatment history, (is)
Column 5
Record, by date, radiological results. Compare each X-ray both with
pretreatment X-ray and with the previous X-ray.
Column 6
Record clinical improvement or deterioration if details are available.
2
Smear
results
3
4
5
6
Culture Susceptibility Radiological Clinical
results
test results
results
status
Drugs taken
(dose, frequency, duration)
i.e.: H300, 7/7, 6 Months
R450, 7/7, 6 Months
Sig, 7/7, 2 Months
c Date of completing or stopping first
course of chemotherapy:.........
d Date of starting second course
of chemotherapy:
Drugs taken
(dose, frequency, duration)
e Date of completing second course
of chemotherapy:...........................
f Date of starting third course of
chemotherapy:
(to be continued...)
Note, this table is a model which you can use enlarged to accommodate the necessary information.
1 8 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
19
ASSESSING THE INDIVIDUAL CASE
faf 4 OF APPARENT MDR TUBERCULOSIS
^*3 ASSESSING THE INDIVIDUAL CASE
4 OF APPARENT MDR TUBERCULOSIS
?
3.3
CONSIDERING THE CRITERIA OF FAILURE OF THE
RETREATMENT REGIMEN
The criteria of failure are mainly bacteriological. But not all positive bacteriological results
necessarily mean “failure". « is)
3.3.1
Report of drug resistance
Do not accept such a report uncritically. As mentioned above, laboratories vary in reliability
and errors may occur. Look at the clinical evidence, especially trends in sputum positivity,
but also trends in the other criteria outlined above. If the susceptibility test results do not fit
in, discuss them with the bacteriologist (if possible) and repeat the test. Don’t rush into
changing treatment. You should decide the appropriate treatment in the light of all the
evidence available for this particular patient.
Persistently positive sputum
a If the patient is still direct smear-positive after 2-3 months of the
retreatment regimen, check carefully that he/she has taken the drugs as
prescribed. This is the commonest cause of “failure”. However, some
patients with severe disease may take longer to convert from sputum
positive to negative. Do not rush into changing treatment. If the number
of bacilli in direct smear is less and he/she is improving clinically and
radiologically, this is particularly reassuring.
b Persistent positivity at 5-6 months makes genuine treatment failure
much more likely. Again the commonest cause is failure to take the
drugs. If you are certain that the patient is taking the drugs, it is highly
probably that the bacilli are resistant to all the drugs he/she is receiving.
Check the apparent persistent positivity by further sputum smears and
culture. For example, occasionally a patient with a large cavity or
cavities may have intermittently positive smears, due to dead bacilli, for
a month or two after negative culture.
If drug susceptibility testing is available, request susceptibility tests on
positive cultures from the sputum specimen collected at 4-5 months in
order that results be available as early as possible.
c Positive culture at the above times is even more important. If direct
smear has become negative, but culture is still positive, e.g. at 2-3
months, this may only be a stage towards complete sputum conversion.
3.3.2
3.3.3
Fall and rise phenomenon
Sputum smear initially becomes negative (or even less positive), and then later becomes
persistently positive. This indicates failure usually due to either the patient having ceased
to take the drugs or sometimes to the development of resistance to all the drugs he/she is
receiving. Check by further cultures and susceptibility tests on positive culture.
20 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
3.3.4
Radiological deterioration?
Deterioration in a chest X-ray may be a sign of failure but deterioration may be due to one
of the following:
a intercurrent pneumonia
b pulmonary embolism
c supervening carcinoma.
A repeat X-ray after 2-3 weeks will probably show improvement in the case of (a) or (b).
Apparent radiological deterioration, if it is not accompanied by bacteriological deterioration,
is less likely to be due to tuberculosis.
3.3.5
Clinical deterioration?
This is the least reliable evidence of failure. It may be due to many conditions other than
tuberculosis. If there is no accompanying bacteriological or radiological deterioration,
clinical deterioration is unlikely to be due to tuberculosis.
3.4
INTERPRETING THE DATA
FOR AN INDIVIDUAL PATIENT
Assess the details of the tabulations you have made (para. 3.2 above). Use the criteria of
failure (para. 3.3) to decide whether resistance was likely to have developed during each
regimen which the patient received. Remember that, if definite failure occurred, (principally
bacteriological failure) it must have been due either to the patient not taking the drugs or to
the development of resistance to all drugs being used (usually for more than 3 months). If
you have all the relevant details, it is usually possible to assess to what drugs the patient's
bacilli will be resistant. This can in due course be confirmed by susceptibility tests.
21
□____________
ASSESSING THE INDIVIDUAL CASE
K 1 OF APPARENT MDR TUBERCULOSIS
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
In general, in cases of failure or relapse following the WHO retreatment regimen, acquired
resistance to isoniazid and rifampicin is highly likely. While waiting for the results of
susceptibility tests, the physician must prescribe a regimen which initially does not contain
isoniazid and rifampicin.
Although it is vital to collect the relevant information if you can, in some cases it may
remain uncertain which drugs the patient has received. Doctors may have neglected serial
sputum tests, or indeed any sputum tests at all. You will therefore have to make the best
estimate you can in the light of whatever evidence is available. This will include what you
know of the most likely (poor) treatment which non-specialist practitioners might have used
in the area where the patient was treated. It may also include what you may know about
the frequency of resistance to individual drugs in that community.
The chosen regimens will consists of a mix of essential drugs, and second-line drugs.
The choice of drugs depends on the interpretation of data collected from each individual
patient.
i
4.1
ESSENTIAL ANTITUBERCULOSIS DRUGS
I
a Streptomycin
Resistance to streptomycin has become less common since the wider
use of ethambutol as a fourth drug in the WHO standard regimen for
new cases, and the use of streptomycin only during the first 2 months in
the WHO standard retreatment regimen.
b Pyrazinamlde
Resistance to pyrazinamide is neither easy to acquire nor to prove by
susceptibility testing. As pyrazinamide has a bactericidal effect in an acid
medium (bacilli inside macrophages), it would be wise to use
pyrazinamide in combination with streptomycin or another
aminoglycoside (active against actively multiplying bacilli, outside
macrophages) to obtain a maximal bactericidal effect against all
populations of bacilli (inside and outside macrophages).
ii
c Ethambutol and thioacetazone
Ethambutol and thioacetazone, when they are used during the
continuation phase of WHO standard regimens (for new cases and
retreatment cases), are probably useless for the treatment of apparent
MDR tuberculosis. If a reliable susceptibility test shows that ethambutol
is still active, this bacteriostatic agent might be valuable as a companion
drug for preventing the emergence of resistance to other active drugs.
Thiacetazone, a very poor bacteriostatic agent, has no place (except as
a last resort) in the treatment of MDR tuberculosis. There is a risk of
cross-resistance with thioamides and additional toxicity when
thioacetazone is associated with a thioamide. (i6;The risk of severe
adverse reactions prohibits the use of this drug in HIV- positive patients.
2 2 GUIOEUNES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
23
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
4.2
SECOND-LINE ANTITUBERCULOSIS DRUGS
(If. 18. 19. 20)
e Para-aminosalicylic acid (PAS)
Second line antituberculosis drug;is are applicable in the treatment of apparent or proved
MDR tuberculosis.
This is a bacteriostatic agent, valuable for preventing resistance to
isoniazid and streptomycin in the past and to other bactericidal drugs today.
Classes of second-line antituberculosis drugs
f Others
a Aminoglycosides
Other drugs, sometimes mentioned as second line antituberculosis
drugs, have no place in the treatment of MDR tuberculosis:
When resistance to streptomycin is proved or highly suspected, one of
the other aminoglycosides can be used as a bactericidal agent against
actively multiplying organisms:
• rifampicin derivatives, like rifabutin (2i), cannot be used since there is
almost complete cross-resistance between rifabutin and rifampicin
(especially when there is acquired resistance to rifampicin);
• kanamycin, the least expensive, but largely used for indications other
than tuberculosis in some countries.
• clofazimine has some activity against Mycobacterium leprae and
Mycobacterium ulcerans, but no activity against Mycobacterium
tuberculosis.
I
• amikacin, as active as kanamycin and better tolerated, but much more
expensive.
• capreomycin/ very expensive but very useful in cases with tubercle
bacilli resistant to streptomycin, kanamycin and amikacin.
4.3
CROSS-RESISTANCE
Consideration of cross-resistance is important for selecting the drugs acceptable for
treatment of apparent or proven MDR tuberculosis. As usual in the treatment of infectious
diseases when the combination of several drugs is required, it is ineffective to combine two
drugs of the same group or to combine in the prescribed chemotherapy regimen a drug
potentially ineffective because of cross-resistance.
3
b Thioamides
Ethionamide or prothionamide are 2 different presentations of the
same active substance, with bactericidal activity. Prothionamide may be
better tolerated than ethionamide in some populations.
c Fluoroquinolones
4.3.1
Ofloxacin and GjpiQfloxacin are two different drugs, but with complete
cross-resistance within the group. These drugs have a low bactericidal
activity, and are useful in association with other drugs. The
pharmacokinetics of ofloxacin are better than the pharmokinetics of
ciprofloxacin. Sparfloxacin should be avoided because of severe
cutaneous side effects (photo-sensitisation). Norfloxacin should not be
used, because it does not give adequate serum levels.
Thioamides and thioacetazone
(16)
Ethionamide, in the group of thioamides, induces complete cross-resistance with
prothionamide. They should be considered as the same drug. Frequently there is also cross
resistance between thioamides and thioacetazone: strains naturally resistant to thioacetazone
are usually still susceptible to ethionamide-prothionamide; strains resistant to ethionamideprothionamide are usually resistant also to thioacetazone, in more than 70% of cases.
d Cycloserine (or terizidone)
This is the same bacteriostatic agent, with 2 different formulations. It has
no cross-resistance with other antituberculosis agents. It might be
valuable to prevent resistance to other active drugs, but its use is limited
by its high toxicity.
4.3.2
Aminoglycosides
• Strains resistant to streptomycin are susceptible to kanamycin-amikacin.
• Resistance to kanamycin induces a complete cross-resistance with
amikacin: they should be considered as the same drug. Resistance to
kanamycin-amikacin induces also resistance to streptomycin.
Sinctly speaking, capreomycin is not an aminoglycoside, but is related m terms of activity and side effects.
24 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
i
• Strains resistant to streptomycin, kanamycin, amikacin are still
susceptible to capreomycin.
25
n
4.3.3
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
Fluoroquinolones
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
(22)
Table Fl
Ofloxacin, ciprofloxacin and sparfloxacin induce complete cross-resistance for all
fluoroquinolones. It is why the use of ofloxacin must be carefully considered, since some
new more active quinolones (e.g. levofloxacin) could replace ofloxacin in the future.
Ranking of antituberculosis drugs for treatment
of MDR Tuberculosis
Rank
Drugs
Average daily
dosage
1
Aminoglycosides
15 mg/kg
Type of
antimycobacterial
activity
Ratio of peak serum
level to MIC
There is no cross-resistance with other classes of drugs.
4.3.4
Cycloserine and terizidone
I
a. Streptomycin
b. Kanamycin
or Amikacin
c. Capreomycin
There is complete cross-resistance between these two drugs: they should be considered
as the same drug. There is no cross-resistance with other classes of drugs.
4.4
CLASSIFICATION OF ANTITUBERCULOSIS DRUGS
FOR TREATMENT OF MDR TUBERCULOSIS
Several criteria are used for classifying antituberculosis drugs available for treatment of
MDR tuberculosis.
4.4.1
IB
bactericidal against
actively multiplying
• organisms
20-30
5-7.5
10-15
5-7.5
2
Thioamides
(Ethionamide
Prothionamide)
10-20 mg/kg
. bactericidal
4-8
3
Pyrazinamide
20-30 mg/kg
bactericidal at acid pH
7.5-10
4
Ofloxacin
7.5-15 mg/kg
weakly bactericidal
2.5-5
5
Ethambutol
15-20 mg/kg
bacteriostatic
2-3
6
Cycloserine
10-20 mg/kg
bacteriostatic
2-4
7
PAS acid
10-12 g
bacteriostatic
100
According to their activity
The main criteria are based on biological data, which determine 3 groups of antituberculosis
drugs available according to their activity and cross-resistance: (17.19.23.24.25)
• drugs with bactericidal activity: aminoglycosides, thioamides and, in
special conditions of pH acid, pyrazinamide
• drugs with low bactericidal activity: fluoroquinolones
• drugs with bacteriostatic effect (when given at usual dosages in man)
e.g.: ethambutol, cycloserine and PAS (Table 2)
i
!
26 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
i
27
n
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
4.4.2
According to some other clinical criteria
4.4.3
AVAILABLE DRUGS FOR MDR TUBERCULOSIS
According to their cost
Apart from the acceptable daily dosages, other criteria should also be considered for
clinical use:
• acceptability to the patient (linked to the bulk or total volume of drug to
be injected or swallowed, painful injection, taste);
• tolerance;
• potential toxicity.
Finally, the crucial criterion for the choice of second-line antituberculosis drugs is the cost
of these drugs. The costs vary considerably from one country to another, according to the
suppliers, the market conditions, and the size of the market (Table 4). Information
regarding suppliers of these drugs and their costs is available on request from WHO and
IUATLD.
Additional criteria result from meta-analysis of several controlled trials conducted before
and after the rifampicin era tzs-ss).
All these characteristics are summarized in Table 3 (see Annex for further details).
Table EJ
Table Fl
Cost of antituberculosis drugs_______
for the treatment of MDR tuberculosis
Rank of choice
Formulation, acceptable daily dosages and main
characteristics of antituberculosis drugs available
for treatment of MDR tuberculosis
Defined daily dose
(DDD)
Cost of 30 DDD (one month) in US dollars
Lowest price
Paris (b)
New York (c)
obtainable (a)
1 Aminoglycosides
Drugs
Formulation
Daily dosage (mg)
Minimum Maximum
Acceptability
Tolerance
a. Streptomycin
b. Kanamycin
or Amikacin
c. Capreomycin
Toxicity
1 Aminoglycosides
a. Streptomycin
b. Kanamycin
Amikacin
c. Capreomycin
vial, 1 g
vial, 1 g
vial, 1 g
vial, 1 g
750
750
750
750
1 000
1 000
1 000
1 000
injection
moderate medium
injection (painful) poor
medium
injection
injection (painful) moderate medium
a. Ethionamide
b. Prothionamide
3 Pyrazinamide
tablet, 250 mg
tablet, 250 mg
500
500
750
750
good
good
moderate medium
moderate medium
tablet, 400 mg
or 500 mg
1 200
1 600
good
moderate low
a. Ofloxacin
b. Ciprofloxacin
tablet, 200 mg
tablet, 250 mg
600
1 000
800
1 500
good
good
good
good
low
low
5 Ethambutol
tablet, 400 mg
1 000
1 200
good
good
low
6 Cycloserine
Terizidone
tablet, 250 mg
tablet, 300 mg
500
600
750
600
good
moderate high
7 EAS
tablet, 500 mg
granules
packet 4 g
10g
10g
12g
12g
bad (bulk, taste)
good
poor
low
moderate low
28 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
Prothionamide
750 mg
92.6
3 Pyrazinamide
1 500 mg
2.9
Ciprofloxacin
1
i
148
14.8
4 Ofloxacin
4 Fluoroquinolones
2.2
10.9
750 mg
2 Ethionamide
2 Thioamides
ig
ig
ig
ig
800 mg
38.4
44.0
641.0
253.0
428.7
9.3
76.05
7.8
59.77
198.2
87.00
1 500 mg
29.4
153.00
5 Ethambutol
1 200 mg
2.3
7.8
70.35
6 Cycloserine
or Terizidone
750 mg
600 mg
63.00
101.00
57.3
179.10
12g
12g
17.00
199.00
7 PAS acid
tablet
granules
239.45
(a) FOB price, special tariff proposed in 1995 to international aid organizations for national tuberculosis programmes
(b) 1996 price in Assistance Publique. Hopitaux de Pans
(c) 1996 price in New York City. Department of Health.
29
3______
CHOOSING A CHEMOTHERAPY REGIMEN FOR
A PATIENT WITH APPARENT MDR TUBERCULOSIS
5.1
BASIC PRINCIPLES
We assume that all patients with apparent drug-resistant tuberculosis will have bacilli
resistant to isoniazid.
Patients with additional resistance, or suspected resistance, to streptomycin and/or
thioacetazone (but not to rifampicin) should respond well to the WHO standard retreatment
regimen (2HRZES/1HRZE) in the initial phase, (i)
The following therefore applies to MDR patients with resistance at least to isoniazid and
rifampicin, patients considered to have failed on the WHO standard retreatment
regimen, and other patients who have received a variety of bad regimens outside national
programmes.
Such patients will often require the use of at least some second-line drugs. These drugs
are less effective and have more side effects than the present standard essential drugs. It
must be made clear to the patient and staff that meticulously taking the prescribed reserve
regimen is all that stands between the patient and death. The patient must try to tolerate
any unpleasant side effects in order to achieve survival. He/she must agree to remain
under direct observation, with each dose supervised, at least until the sputum is negative.
The patient must receive clear and complete explanations before treatment, and
permanent psychological support and attention.
In designing a regimen do not aim to keep drugs in reserve. That is the way to lose one
battle after another. The patients has already lost several battles. This last battle must be
won. As outlined above, decide to what drugs the patient’s bacilli are, or likely to be, still
sensitive. Then prescribe what is likely to be the most effective regimen available to
him/her.
In the first place prescribe drugs which the patient has not had previously. The bacilli
are fairly certain to be sensitive to these. The practice of adding isoniazid to these drugs
confers no advantage.
I
If, on the evidence, it is possible that the bacilli remain sensitive to a "standard” drug (para.
4.1), in spite of the patient having received it in an unreliable combination, you may add it
to the regimen in case it is still useful but do not rely on it to prevent further resistance; if
tests later show resistance to that drug, you may have failed to protect the newly
introduced drugs. On the other hand, if the bacilli turn out to be still sensitive to it, it will
give an additional effect. This may later, after you have the results of resistance tests,
permit you safely to withdraw a weaker second-line drug which is causing the patient side
effects, but still leave an effective regimen which will prevent further resistance.
The initial regimen should consist of at least three drugs, preferably four or five, to which
the bacilli are likely to be fully sensitive, i.e. drugs not previously used for that patient.
Among these drugs, it is desirable to use in combination an injectable aminoglycoside
(according to the rank of choice) and pyrazinamide (even if previously used, because
resistance is usually unlikely). This combination has a good bactericidal aclivilx^. .
>\
I
i
05621
,0Js
CHOOSING A CHEMOTHERAPY REGIMEN FOR
A PATIENT WITH APPARENT MOR TUBERCULOSIS
F”*!] CHOOSING A CHEMOTHERAPY REGIMEN FOR
L£jAPATIENT WITH APPARENT MDR TUBERCULOSIS
When the patient’s sputum has converted to negative, you can withdraw one or more
drugs, preferably a weaker drug which is causing side effects.
Table g
The treatment with these weaker regimens should be continued for at least 18 months after
sputum conversion to prevent relapse.
Acceptable “third-line" regimen before (or without)
susceptibility test results
Initial phase__________
Minimum duration
in months______
1 Aminoglycoside*
3
2 Ethionamide
3
3 Pyrazinamide
3
4 Ofloxacin6
3
Drugs
In any regimen chosen, especially when weaker drugs are used, the treatment should be
given daily and should be directly observed. It is also mandatory to monitor bacteriological
results (smear and culture) monthly from the second month until the sixth month, and then
quarterly until the end of treatment.
Drugs
Continuation phase
Duration in months
1 Ethionamide
2 Ofloxacin6
Kanamycin. or amikacin, or capreomycin
The daty dosed800 mg can be reduced to 400 mg if poorly tolerated. Ifofloxac^ « not available.
5.2
EXAMPLES OF ACCEPTABLE REGIMENS IN
PROGRAMME CONDITIONS
18
use cydosenne
(34. 35. 36. 37. 38)
5.2.2
In programme conditions, even in specialized units in connection with a reliable laboratory,
susceptibility test results are not obtainable immediately: a delay of 2-4 months is usual.
Sometimes, the results cannot be obtained for various reasons: initial cultures negative or
contaminated; failures in logistics (transport of specimens, temporary shortage of reagents,
etc.). In practice, two situations should be considered depending on the availability of
susceptibility test results.
Situation A: Susceptibility test results are not available
before starting the new treatment
A new chemotherapy regimen should be initiated before receiving susceptibility test results.
• In this situation, after a failure of the WHO standard retreatment
regimen, a third line" regimen should be prescribed containing:
- at least 3 drugs never used: kanamycin, ethionamide, ofloxacin
- and pyrazinamide.
• After bacteriological conversion (usually after three to four months), if
the initial susceptibility test results cannot be obtained, the continuation
phase during 18 months should employ the two drugs best tolerated
and more usually more active: ethionamide and ofloxacin. (Table 5)
Situation B: susceptibility test results are available,
either before prescribing a new treatment, or during the initial phase of the regimen
prescribed in situation A. Several regimens are acceptable, depending on the results of
susceptibility tests.
5.2.2.1
5.2.1
18
Resistance to isoniazid, but rifampicin still active
• Resistance to isoniazid alone or in combination with resistance to
streptomycin (and/or with thioacetazone).
I
i
It may be simplest to use the WHO standard retreatment regimen during
the first three months (2SERHZ/1ERHZ), though isoniazid and
streptomycin are redundant and could be omitted. After smear
conversion, use rifampicin and ethambutol until the end of the ninth
month.
• Resistance to isoniazid and ethambutol (with or without resistance to
streptomycin)
Use rifampicin and ethionamide for nine months at least, with
pyrazinamide and one aminoglycoside (kanamycin or amikacin if
resistance to streptomycin; capreomycin if resistance to streptomycin
and kanamycin) during the initial phase until smear conversion.
If ethionamide is not available, ofloxacin can be used. (Table 6)
32 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
33
CHOOSING A CHEMOTHERAPY REGIMEN FOR
A PATIENT WITH APPARENT MDR TUBERCULOSIS
pw CHOOSING A CHEMOTHERAPY REGIMEN FOR
A PAT
Table
Table H
Resistance to
•'■‘i
Initial phase
Drugs
• Isoniazid
(streptomycin,
thioacetazone)
1 rifampicin
2 aminoglycoside'
3 pyrazinamide
4 ethambutol
2-3
2-3
2-3
2-3
1 rifampicin
2 ethambutol
• Isoniazid and
ethambutol
(streptomycin)
1 rifampicin
2 aminoglycoside'
3 pyrazinamide
4 ethionamide*1
3
3
3
3
1 rifampicin
2 ethionamide*1
•• •
“
Continuation phase
Minimum
duration
in months
Drugs
Resistance to
6
6
6
6
Resistance to at least isoniazid and rifampicin
• Resistance to isoniazid and rifampicin (with or without resistance to
streptomycin)
w
When the two most important antituberculosis drugs are not active a
five-drug regimen is mandatory.
I
Continuation phase
Initial phase
Drugs
Minimum
duration
in months
• Isoniazid,
rifampicin and
streptomycin
1 aminoglycoside’
2 ethionamide
3 pyrazinamide
4 ofloxacin1
5 ethambutol
3
3
3
3
3
1 ethionamide
2 ofloxacin1
3 ethambutol
18
• Isoniazid,
rifampicin,
streptomycin,
and ethambutol
1 aminoglycoside’
2 ethionamide
3 pyrazinamide
4 ofloxacin1
5 cycloserine8
3
3
3
3
3
1 ethionamide
2 ofloxacin1
3 cycloserine8
18
18
18
Duration
in months
S""
'r reS‘S'anCe t0
ws kanamycm or capreomycm
H ethK^miOe « not available or poorly tolerated (even'at a dose of 500 mg^da^S'^aoin.
5.2.2.2
Acceptable “third line’’ regimen for the treatment
of MDR Tuberculosis
Drugs
Duration
in months
18
18
* Karamycin or amikacin, or capreomycin
' The daily dose of BOO mg can be reduced to 400 mg it poorly tolerated
9 PAS it cycloserine is not available or too toxic.
Usually, reliable information on susceptibility of M. tuberculosis to pyrazinamide is not
available. But if the resistance to pyrazinamide is duly proven and compatible with clinical
data, pyrazinamide should be stopped and cycloserine or PAS may be included in the
regimen.
During the initial phase, use ethionamide plus ofloxacin plus another
bacteriostatic drug (ethambutol if possible) with pyrazinamide and an
aminoglycoside available for a minimum of 3 months, or until smear
conversion.
During the continuation phase, use ethionamide plus ofloxacin plus
another bacteriostatic drug for at least 18 months after smear
conversion (Table 7).
• Resistance to isoniazid, rifampicin, ethambutol (with or without
resistance to streptomycin)
During the initial phase, use ethionamide plus ofloxacin plus another
bacteriostatic drug (cycloserine or PAS) with pyrazinamide and an
aminoglycoside available for a minimum of 3 months or until smear
conversion During the continuation phase, use ethionamide plus
ofloxacm plus cycloserine (or PAS) for at least 18 months after smear
conversion (Table 7).
34 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
35
a_______
THE PLACE OF SURGERY
6.1
(39 40)
INDICATION FOR SURGERY
Surgery should be considered for a patient with bacilli resistant, or probably resistant, to all
except two or three relatively weak drugs. Unfortunately many such patients will have too
extensive disease and/or too poor lung function for surgery to be possible. If the patient
has a large localised cavity with little other disease, reasonable lung function and only two
or three (weak) drugs available, surgery should be seriously considered.
.1
6.2
TIMING OF SURGERY
To avoid serious, and potentially fatal tuberculosis complications of surgery, operate when
the bacillary population is likely to be at it lowest. If only a very weak regimen is available,
experience has shown that the most favourable time is after two months’ treatment.
6.3
ANTI-TUBERCULOSIS CHEMOTHERAPY
AFTER SURGERY
After surgery, the same regimen should be continued for at least 18 months.
!
K-;'
a?!
37
ANNEX
SECOND-LINE ANTITUBERCULOSIS DRUGS
• AMINOGLYCOSIDES
- Kanamycin and amikacin
- Capreomycin
• THIOAMIDES
- Ethionamide
- Prothionamide
• FLUOROQUINOLONES
- Ofloxacin
- Ciprofloxacin
• CYCLOSERINE (AND TERIZIDONE)
• PARA-AMINOSALICYCLIC ACID (PAS)
Kanamycin and Amikacin
saHsi
These are bactericidal agents of the aminoglycoside class, obtained from a streptomyces.
Their bactericidal effect in vitro and in vivo against Mycobacterium tuberculosis is very
similar and their adverse reactions are those of other aminoglycosides.
Their bactericidal effect might be valuable in patients with bacilli resistant to streptomycin.
Cross-resistance between kanamycin and amikacin is usual.
Preparation and dose
The drugs are presented as sterile white powder for intramuscular injection in sealed vials
containing the equivalent of 250 mg, 500 mg or 1 g of drug. The drug should be dissolved
in 2 ml of 0.9% sodium chloride injection or water for injection.
■
'
'
■
The optimal dose is 15 mg/kg bodyweight, usually 750 mg to 1 g given daily or five days
per week, by deep intramuscular injection. Rotation of injection sites avoids local
discomfort. The duration of daily therapy is usually 3 to 4 months. When necessary, it is
possible to give the drug at the same dose 2 or 3 times weekly during the continuation
phase, under close monitoring for adverse reactions.
Adverse reactions
These are similar to the side-effects associated with streptomycin and capreomycin.
Ototoxicity, deafness or vertigo may occur. Reversible nephrotoxicity may occur.
' IO
./
•
•'
39
ANNEX
ANNEX
Precautions
Before the rifampicin era, ethionamide (or prothionamide, the drug is similar in its
antibacterial effects and adverse reactions) was a basic component of retreatment regimen
for tuberculosis patients with bacilli resistant to isoniazid and streptomycin.
In patients with impaired renal function, the daily dose should be reduced and/or the
intervals between doses increased, to avoid accumulation of the drug. In these patients,
renal function should be monitored regularly during use. This drug should not be used in
pregnant women except as a last resort.
Presentation and dose
Ethionamide and prothionamide are normally administered in the form of tablets containing
125 mg or 250 mg of drug. The maximum optimum daily dose is 15-20 mg/kg or 1 g. The
usual dose is 500 mg to 1 g daily, depending upon body weight and tolerance. Few
persons can take more than 750 mg daily. (750 mg for patients weighing 50 kg or more,
500 mg for patient weighing less than 50 kg)
Capreomycin
This is a bactericidal agent from the aminoglycosides class, obtained from Streptomyces
capreolus.
Patients may find the drug was more acceptable if it is administered with orange juice or
milk or after milk, or at bed-time to avoid nausea. Among patients on directly observed
treatment, a daily dose of 750 mg can be given as 250 mg under strict observation and 500
mg self-administered 10-12 hours later.
Its bactericidal effect might be valuable in patients with bacilli resistant to streptomycin,
kanamycin and amikacin: there is no cross-resistance with the other aminoglycosides.'
Adverse reactions
Preparation and dose
Prothionamide is generally considered to be less unpleasant and better tolerated than
ethionamide. But adverse reactions are essentially similar. The main troubles are epigastric
discomfort, anorexia, nausea, metallic taste and sulphurous belching. Vomiting and
excessive salivation can occur. Tolerance varies in different populations: the drug is usually
well tolerated in Asia and in Africa.
Capreomycin sulphate is supplied as a sterile white powder for intramuscular injection in
sealed vials each containing 1000 units approximately equivalent to 1g capreomycin base.
This should be dissolved in 2 ml of 0.9 per cent sodium chloride injection in water. Two or
three minutes should be allowed for complete solution. The usual dose is 1g in a single
dose daily, not exceeding 20 mg/kg for 40-120 days after which the dose must be reduced
to 2/3 times weekly, as the risk of important side-effects rises sharply at that time.
Adverse reactions
MS
These are similar to the side-effects with streptomycin, mainly tinnitus and vertigo with a
lesser risk of deafness. Kidney damage may occur with elevation of serum and urine
creatinine. Hypokalaemia, hypocalcaemia and hypomagnesaemia have also been
reported. General cutaneous reactions and hepatitis may occur rarely. There may be pain
and swelling at injection sites if it is not given by deep intramuscular injection.
Precautions
Capreomycin should be avoided if possible in patients with impaired hearing or renal
function. Serum urea and electrolytes should be monitored during treatment. It is contra
indicated in pregnancy and best avoided in children.
Ethionamide (or Prothionamide)
■■-s •
These are bactericidal agents from the class of thioamides. Their chemical structure
resembles thioacetazone with which there is frequent and partial cross-resistance.
(Bacilli resistant to thioacetazone are often sensitive to thioamides, but the reverse is
seldom the case).
4 0 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
I
Psychotic reactions including hallucinations and depression may occur. Hypoglycaemia is
a rare but dangerous occurrence, obviously particularly important in diabetic patients.
Hepatitis may occur in about 10% of cases, but is rarely serious. When major liver damage
occurs, jaundice and highly symptomatic disease is created, with prolonged elevation of
transaminases (6-8 weeks) and drug administration should be interrupted. Other rare side
effects have included gynaecomastia, menstrual disturbance, impotence, acne, headache
and peripheral neuropathy.
Precautions
This drug should not be administered in pregnancy as it has been shown to be teratogenic
to animals. It should be very carefully monitored if given to patients with diabetes, liver
disease, alcoholism or mental instability.
Ofloxacin and Ciprofloxacin
These are weakly bactericidal agents of the fluoroquinolones class. Both ofloxacin and
ciprofloxacin have a bactericidal effect in vitro against Mycobacterium tuberculosis.
Although neither drug has been studied extensively in controlled clinical trials, evidence
suggests that they are equivalent in therapeutic efficacy when one of these is used, along
with other effective drugs.
41
' !||| ANNEX
ANNEX
There is no cross-resistance with other antituberculosis agents, but complete cross
like TvonoxaciT0 Ofl°XaCin and CiprOfl°XaCin (and between the 0,her fluoroquinolones
the continuation phase more than 500 mg daily. The daily dose can be given in two intakes:
- cycloserine: 250 mg, in the morning, and 500 mg 12 hours later.
Presentation and dose
- terizidone: 300 mg twice a day at 12-hour intervals.
Fluoroquinolones are supplied in the form of tablets containing:
Adverse reactions
- 200 mg of ofloxacin
• 250 mg of ciprofloxacin
dai\d°Se iS 600’80° m9 (3’4 ,able,s) °f ofloxacin
1000-1500 mg (4-6 tablets)
of ciprofloxacin during initial phase. If the dose of 800 mg is poorly tolerated the dailv dose
^noleV6/Uded ^°0 m9- °floxacin) durin0 the continuation phase. Either can be given in
xsasrin direc,iy observed ,rea,men,) °r ,he dai,y d°se
Adverse reactions
Precautions
••.-.A*»
These include dizziness, slurred speech, convulsions, headache, tremor, insomnia,
confusion, depression and altered behaviour. The most dangerous risk is that of suicide so
^actioTo/hepttitS6^117 WatChed’ Vefy rarely th®re may be a Qeneralised hypersensitivity
Precautions
In view of the above adverse reactions, monitoring for central nervous system reactions is
essential when cycloserine is prescribed. To prevent minor adverse reactions like
insomnia, administration of small doses of a tranquilliser is sometimes recommended
Pyridoxine may decrease central nervous system effects. The nurses in charge of
treatment of inpatients and the families of outpatients should be warned to report any
undue depression or personality change immediately.
Cycloserine (and terizidone) should be avoided in patients with a history of epilepsy,
mental illness or alcoholism. It should be used very cautiously in patients with renal failure.
SXXX lX?oPScXneOr 9rOWin9 Chi'dren bedaUSe *W
sucrXte0'drU9 interaCti°n'the ,ollowins dru9s should be avoided: antacids, iron, zinc,
Cycloserine (or Terizidone)
Para-Aminosalicylic Acid (PAS)
This is a bacteriostatic agent: its principal value was as an effective companion drug to
isoniazid, preventing the emergence of isoniazid-resistant organisms. PAS was commonly
used 30 years ago, but rarely nowadays.
Preparation and dose
m^rine,iS bac,eriostatic al the usual dosage. Terizidone is a combination of two
■■
PAS is bulky and unpleasant to take because of gastrointestinal discomfort.
Two presentations are available on the market:
* Tablets, sugar-coated, containing sodium salt: sodium para
aminosalicylate, each tablet containing 0.5 g of PAS
Preparation and dose
The drug is given orally in tablets
or capsules containing:
- 250 mg of cycloserine
- 300 mg of terizidone.
So mn AHUm Hai,y dcSe * 15‘2° mg/kg: the usual dose is
mg of cycloserine
600 mg of terizidone. Few patients tolerate more than 750 mg daily, and in
42 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
- Granules of PAS with an acid-resistant outer coating rapidly
dissolved in neutral media. Granules are supplied in packets
containing 4 g per packet.
The daily dosage of the usual tablet preparation is 150 mg/kg or 10-12 g daily in two
divided doses. The recommended schedule is 5 to 6 g (10 to 12 tablets) every 12 hours
The daily dosage of the granular preparation is the same. There is some evidence that a
ower dose of 4 g every 12 hours (8 g/day) of the granular preparation is associated with
good blood levels and improved tolerance.
43
|j^|
REFERENCES
Adverse reactions
The main adverse reactions are gastrointestinal disturbance and general skin or other
hypersensitivity including hepatic dysfunction. Hypokalaemia may also occur.
T^v mT k3?63' ^nS and abdominal discomfort are more common than diarrhoea
thal one shot d notTnnr ad™™S,er!ng ,ha dru9 after ,ood °r with milk. Our experience is
nationt h
n° enquire of the Patient how well he/she is tolerating the drug The
SXhfi
expevnence nausea and VOmiting is much mor® like|y to do so. Wait
over a few Says.00^
S‘
" neCeSSary lower the dose sli9htly and then increase
si©
WWiM
■m
fiiB
h^l^9aentfhdmin2Str« tiOnin large doses may Pr°duce hypothyroidism and goitre as PAS
has an antithyroid effect. These will reverse when the drug is withdrawn.
Precautions
in renal failure 3S may make acidosis worse. The sodium salt should
hT W^en a restncted sodium intake is indicated. The old preparation (tablets)
'TfnI r lhe.abso7t,°n of rifampicin, on account of an excipient (bentonite) The new
1
Treatment of tuberculosis: Guidelines for national programmes. WHO, Geneva, 1993.
2
Kochi A, Vareldzis B, Styblo K. Multidrug resistant tuberculosis and its control
Res. Microbiol., 1994, 144:104-110.
3
Crofton J. Multidrug resistance: danger for the Third World. In Porter JDH, McAdam
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4
Crofton J. Failure in the treatment of pulmonary tuberculosis: potential causes and
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5
Crofton J. The prevention and management of drug resistant tuberculosis.
Bull. Intern. Un. Tuberc., Lung Diseases, 1987, 62 (1-2): 6-11.
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Vareldzis BP, Grosset J, de Kantor I, Crofton J, Lazslo A, Felten M, Raviglione MC,
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7
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8
Cohn D, Bustreo F, Raviglione M. Drug resistance in tuberculosis:
review of worldwide situation and WHO’s global surveillance project.
Clin. Infect. Dis., 1996 (in press).
9
Chaulet P, Raviglione M, Bustreo F. Epidemiology, control and treatment of multidrug
resistant tuberculosis. Drugs, vol. 52, supplement 2, 103-108.
10
Bennett D, Watson J, Yates M, Jenkins T, Mae Guink S. The UK Mycobacterium
Resistance Network, 1994. Tuberc. Lung Dis., 1994, 75 (S2): 99.
11
Schwoebel V, de Benoist AC, Decludt B, Haeghebaert S, Vincent V, Torrea G,
Perronne C, Grosset J. Resultats de la surveillance de la tuberculose a bacilles
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nntln
S2 £XWde
With rifamPiCin abSOrPtiOn-A Urine test for the drug
i
S»
;
■
12 Chan SL. Chemotherapy of tuberculosis. In "Clinical Tuberculosis ed by Davies PDO
Chapman and Hall, London, 1994, p. 141-156.
s»»
13 ?hau,et P* Zidouni N- Fai|ures in tuberculosis chemotherapy. In "Tuberculosis", edited
by Gangadharam PRJ, 1996 (in press).
14 Mazoum L, Zidouni N, Boulahbal F, Chaulet P. Treatment of failure and relapse cases
of pulmonary tuberculosis within a national programme based on short- course
chemotherapy (preliminary report). TSRU, Progress Report, 1992, Vol. 1: 36-42.
was
X
15 Stewart SM, Crofton JW. The clinical significance of low degree of drug
resistance in
pulmonary tuberculosis. Am. Rev. Respir. Dis., 1964, 89: 811-829.
1 Home N W. Modem Drug Treatment o! Tuberculosis. 7lh edition. Ed. CHSA, London, 1990.
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l^l REFERENCES
1
16 Grosset J, Benhassine M. La thiacetazone (Tbl): donndes expdrimentales et
cliniques recentes. Adv. Tuberc. Res., 1970, 17: 107-153.
17 Grosset J. Hierarchie des medicaments antibacillaires: donndes biologiques. In XVII
Congres National de la Tuberculose et des Maladies Respiratoires, Clermont-Ferrand
1974, Masson et Cie, Paris, 1974,1-25.
18
NW‘ M°dem dru9 treatment of tuberculosis (including prevention and control)
7th ed., London, Chest, Heart and Stroke Association, 1990.
19 Jancik E. Effets des agents antibacillaires dits secondaires sur la tuberculose
pulmonaire in: Progr. Expl. Tub., Vol 13, Karger, Bale-New York, 1964, pp. 121-128.
31
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International Union against Tuberculosis. A comparison of regimens of ethionamide
pyrazmamide and cycloserine in retreatment of patients with pulmonary tuberculosis
Bull. Int. Union Tuberc., 1969, 42: 7-57.
32 Chaulet P, Adberrahim K, Zirout A, Ait Khaled N. Resultats de la chimiotherapie de
relais ambulatoire des tuberculeux. In: Chaulet P, Larbaoui E. ed., Acquisitions
recentes sur la tuberculose en Algeria, 1970, SNED Alger, 1971, pp. 134-142.
33 Hong Kong Tuberculosis Treatment Services, Brompton Hospital, British Medical
Research Council Investigation. A controlled clinical trial of daily and intermittent
regimens of rifampicin plus ethambutol in the retreatment of patients with pulmonary
tuberculosis in Hong Kong. Tubercle, 1974, 55:1-27.
■
20 Citron KM. Drug resistance in respiratory tuberculosis: chemotherapy with reserve
drugs.ln: Recent advances in respiratory tuberculosis, 6th Ed., pp. 90-123.
21 Pretet S, Lebeau A, Parrot R, Truffot C, Grosset J, Dinh Xuan AT. Combined
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-?1
chemotherapy including rifabutin for rifampicin and isoniazid resistant pulmonary
tuberculosis. Eur. Resp. J., 1992, 5: 680-684.
22 Sullivan AE, et al. Emergence of fluoroquinolone resistant tuberculosis in New York
City. Lancet, 1995, 345:1148-1150.
34 Ait Khaled N, Benadjila H, Loucif MS, Mounedji A, Chaulet P. Enquete therapeutique
controlee sur trois regimes de chimiothdrapie de reserve (dont un de courte duree)
dans la tuberculose pulmonaire. Bull. Int. Union Tuberc., 1976, 1: 99-106.
35 Swai OB, Aluoch JA, Githui WA, et al. Controlled clinical trials of a .vmh.i.
a regimen of two
durations for the treatment of isoniazid resistant pulmonary tuberculosis
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36 Goble M, Iseman MD, Madsen LA, Waite D, Ackerson L, Horsburgh CR. Treatment of
171 patients with pulmonary tuberculosis resistant to isoniazid and rifampicin
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23 Truffot-Pernot C, Ji B, Grosset J. Activities of pefloxacin and ofloxacin against
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24 Ji B, Truffot-Pernot C, Grosset J. In vitro and in vivo activities of sparfloxacin
37 Iseman MD. Treatment of multidrug resistant tuberculosis.
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. ..A;;;?
25 Latande V, Truffot-Pernot C, Paccaly Moulin A, Grosset J, Ji B. Powerful bactericidal
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26 East African/British Medical Research Council Retreatment Investigation.
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tuberculosis in East Africa. Tubercle, 1971,52: 191-198.
«■!
■
27 Somner AR, Brace AA. Ethionamide, cycloserine and pyrazinamide used successfully
in ttie treatment of chronic pulmonary tuberculosis. Tubercle, 1962, 42: 345.
28 Zierski M Treatment of patients with cultures resistant to the primary antituberculosis
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29 British Tuberculosis Association. Ethionamide, cycloserine and pyrazinamide in the
treatment of drug resistant tuberculosis. Tubercle, 1963, 44: 195-214.
38 Bouvet E. Les tuberculoses multiresistantes. Press Med., 1995, 25 (8): 393-398.
39 Harkin TJ, Harris HW. Treatment of multidrug resistant tuberculosis.
Stuart G: Tuberculosis, Little Brown and Co.^New York, 1996, pp. 843-85(1
N
40 Hong Kong Chest Service/British Medical Research Council. A controlled study of
rifabutin and an uncontrolled study of ofloxacin in the retreatment of patients with
pulmonary tuberculosis resistant to isoniazid, streptomycin and rifampicin
Tubercle Lung Disease, 1992, 73: 59-67.
41
Iseman MD Madsen L, Goble M, et al. Surgical intervention in the treatment of
pulmonary disease caused by drug resistant Mycobacterium tuberculosis
Am. Rev. Resp. Dis., 1990, 141: 623-625.
42 Mahmoudi A, Iseman MD. Surgical intervention in the treatment of drug resistant
tuberculosis. Am. Rev. Resp. Dis., 1992: 145, A816.
30 Jancik E, Zelenka M, Tousek J, Makova M. Chemotherapy for patients with cultures
resistant to streptomycin, isoniazid and PAS. Tubercle, 1963, 44: 443- 451.
-
-
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4 6 GUIDELINES FOR THE MANAGEMENT OF DRUG-RESISTANT TUBERCULOSIS
47
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The views expressed In documents by named authors are solely
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responsability of thnRG
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© World Health Organization
1997
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