Irrational speech occurring in the course of anti-tuberculous therapy--possibly caused by isoniazid

Two girls, both aged 11 years, one with pulmonary tuberculosis and the other with abdominal tuberculosis, were admitted to the Wesley Guild Hospital, Ilesha, Nigeria during the months of June and October, respectively, in 1989. During the course of treatment with combination chemotherapy, both developed irrational speech which responded to temporary withdrawal of isoniazid from the combination. Subsequent progress was uneventful.