Options on TB Chemotherapy
Item
- Title
- Options on TB Chemotherapy
- Creator
- Paul Shears
- Date
- 1985
- extracted text
-
Options on T.B
Chemotherapy
Studies show 50% failure rate in most TB programmes - primarily
due to defaulting from treatment. In the common treatment regimes
based on Streptomycin, isoniazid and thiacetazone, the required
duration of 18 months treatment is the major reason for the high
default rate. Controlled trials have shown 100% success with
regimes based on rifampicin, isomazid and pyrazinamide, but with
ensured 100% compliance. There is scope to get a compromise between
the low success of most programmes in the field, and the results
of controlled trials. The compromise approach is based on the
object NOT of getting 100% success, but of, say, 70% success, which
would still be a great improvement over current programmes.
Table 1 shows the results from a number-of trials. Instead of
concentrating on those that give 100% success, let us look at
those that give 70% success, io., trials 8 and 9O These results
* have usually not been considered further, because a 30% failure
rate is 'not acceptable'. Yet in most programmes in the field we
are accepting a 50% failure rate.
Trials show that with a four month regime, only the first two
months with rifampicin, 70% success can be achieved (assuming
90-100% drug compliance during the four month period).
If patients, and community h .alth workers had to aim for good
drug compliance for 4 months instead of 18 months, we may be
setting more realistic targets. Obviously if a patient were still
attending at 4 months, we should attempt to continue isomiazid/
thiaceia zone for another 2 tc 4 months, but even if default
occurred during this period, we would still be achieving 70%
success.
Such ideas may not be acceptable to most physicians, but so long
as programmes are based on regimes that aim for 100% success but
which are not r alistic in most rural or poor urban areas, we are
likely tc continue to lose the battle against TB.
\
TABLE 1 (All trials based on sputum positive patients).
== — = — =:
Relapse rate 2 'yrs
Trial Regime
after end of trea'tNox _
1
5
Standard 1 yr to 18 mths of
2 SHRZ/4HRZ
2 SHRZ/4HR
2 SHRZ/2HRZ
2 SHRZ/2HR
6
7
8
2 SHRZ/2HRZ
2 SHRZ/2HR
2 SHRZ/2HZ
4 months
16%
4 months
4 months
11%
3 2%
9
2 SHRZ/2H
4 months
30%
2
3
4
3 SHT/15HT
50% in most program
6 months
6 months
4 months
0
2%
10%
8%
4 months
Sources: 2-5 Tubercle 62 pp 95-101 (Heng Kong Data)
6-9 Am. J Resp. Dis.• 123 p. 165 (E. Africa Data)
Keys S = Streptomycin;
Z = Pyrazinamide
H = Isoniazid;
R = Rifampicin
eg. 2 SHRZ/4HRZ = Two months streptomycin, isoniazid, rifampicin,
pyrazinamide followed by four months isoniazid, rifampicin,
pyrazinamide.
- Paul Shears, Oxford s Dec 1984
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