Objective: To describe a case of isoniazid-associated psychosis and review the incidence of this adverse effect.
Data sources: Information about the patient was obtained from the medical chart. A MEDLINE search of the English-language literature published from 1950 to 1992 was conducted and Index Medicus was manually searched for current information.
Study selection: All case reports describing isoniazid-associated psychosis were reviewed.
Data extraction: Studies were evaluated for the use of isoniazid, symptoms of psychosis, onset of symptoms, and dosage of isoniazid.
Data synthesis: The case report is compared with others reported in the literature. The incidence of isoniazid-associated psychosis is rare.
Conclusions: The mechanism of isoniazid-associated psychosis is uncertain. It appears that isoniazid was associated with the psychosis evident in our patient and in the cases reviewed.