SHORT-COURSE CHEMOPROPHYLAXIS WITH RIFAMPICIN, ISONIAZID AND PYRAZINAMIDE FOR TUBERCULOSIS EVALUATED IN GOLD MINERS WITH CHRONIC SILICOSIS - A DOUBLE-BLIND PLACEBO-CONTROLLED TRIAL
Rl. Cowie, SHORT-COURSE CHEMOPROPHYLAXIS WITH RIFAMPICIN, ISONIAZID AND PYRAZINAMIDE FOR TUBERCULOSIS EVALUATED IN GOLD MINERS WITH CHRONIC SILICOSIS - A DOUBLE-BLIND PLACEBO-CONTROLLED TRIAL, Tubercle and lung disease, 77(3), 1996, pp. 239-243
Setting: A medical facility for approximately 90 000 gold miners emplo
yed on 24 South African gold mines. Objective: To evaluate the effecti
veness of rifampicin, isoniazid and pyrazinamide given for 3 months fo
r the prevention of tuberculosis in men with silicosis. Design: A rand
omised double-blind placebo controlled trial with active 4-year follow
up of subjects by routine radiographic screening. Results: A total of
382 gold miners with silicosis were randomised to receive rifampicin
600 mg, isoniazid 400 mg and pyrazinamide 1.25 g daily as Rifater(R) o
r a placebo. These men have been followed for 4 years since the end of
the treatment period. Eleven men who received the combination tablet
and 15 men who received the placebo tablet have developed tuberculosis
(chi(2) dfl = 0.66, P = 0.4). Conclusion: This multi-drug short cours
e chemoprophylaxis regimen has failed to prevent tuberculosis in miner
s with silicosis. Even if a larger study had demonstrated a statistica
lly significant effect of the regimen as compared with placebo, the ra
te of tuberculosis in the men who received the three-drug regimen was
unacceptably high.