A second international co-operative investigation into thioacetazone side-effects. 1. The influence of a vitamin and antihistamine supplement.

As part of a large-scale international, co-operative investigation into the side-effects produced by thioacetazone employed in the treatment of tuberculosis, an evaluation has been made of a supplement incorporating vitamins and an antihistamine as a prophylactic.Over a 12-week period of treatment, the additive supplement failed to reduce the over-all frequency of side-effects or the frequency of side-effects leading to a major departure from prescribed treatment. There was also no evidence that the more serious side-effects, particularly rashes, jaundice and agranulocytosis, were reduced by the additives, although the occurrence of vomiting, which was however infrequent, was reduced.In view of this lack of appreciable benefit, as well as the higher cost and impaired keeping properties of tablets containing thioacetazone plus isoniazid when the supplement is added, the use of the supplement as a prophylactic cannot be recommended.