Thiacetazone toxicity in the treatment of tuberculosis patients in Nigeria.

In a series of 1,212 tuberculosis patients treated on a regime of streptomycin/isoniazid/thiacetazone (S/INH/thiacetazone) over a period of 10 years in Nigeria there were 171 cases considered to have toxic reactions to thiacetazone (14%). 134 of these (11%) were sufficient to require a change of treatment. Giddiness and rashes were the commonest effects, the former occurring mainly in association with streptomycin, and considered to be largely due to potentiation of streptomycin toxicity by thiacetazone. The advantages of the S/INH/thiacetazone regime in Nigeria are considered to outweigh the disadvantages, so long as necessary precautions are taken to keep the effects of toxicity to a minimum.