Interventions for Tuberculosis Control and Elimination 2002

medications were taken daily throughout the course of treatment. 122 In
Poland, a study with this regimen, with the continuation phase given twice
weekly, led to neither failures nor relapses. 525 Similar good results were
obtained with the same regimen in Singapore, with the continuation given
thrice weekly. 617
Most industrialized countries have adopted this regimen, given daily
in the intensive phase and daily or intermittent in the continuation phase,
as their regimen of choice for patients without a history of prior treatment.
12-month regimens
The best documented 12-month regimen currently used in low-income countries
consists of 12 months of isoniazid plus thioacetazone, supplemented
by streptomycin during the first two months. 122 This regimen has been
widely used in IUATLD collaborative programs in patients without a prior
history of treatment. Amongst these, it is given for cases with positive
sputum smears who cannot receive a directly observed rifampicin-containing
intensive phase and for the majority of patients whose sputum smears
are negative or who have extrapulmonary tuberculosis which is not lifethreatening.
In Uganda, the frequency of adverse drug events and survival as the
main outcomes of interest were compared for the above 12-month regimen
and a nine-month, rifampicin-throughout regimen (supplemented by pyrazinamide
during the first two months) among HIV-infected patients. 618 As expected,
adverse drug events were much more common in the former than the
latter regimen, but survival over a two-year follow-up period was identical.
In Malawi, HIV-infected patients with sputum smear-negative tuberculosis
who were treated with a 12-month regimen (12 months of isoniazid
plus thioacetazone or ethambutol, supplemented with streptomycin during
the first month), had a very high relapse rate approaching 20% (compared
to seven per cent among HIV-negative patients). 590 These findings critically
challenge the continued use of such a regimen in countries where the
prevalence of HIV infection among tuberculosis patients is high.
Choice of re-treatment regimen
Treatment regimens for a national tuberculosis control program should be
designed to allow curative treatment of patients requiring a re-treatment
regimen, because it is the patient’s last chance to get cured. The need for
a re-treatment regimen is based on the increased probability of resistance
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