Cases of isoniazid-related psychiatric disordersreported in the literature include psychosis, obsessive–compulsive neurosisand mania. Tuberculosis is an endemic issue in our area; so much people receiveprophylactic treatment for tuberculosis. Pyridoxine deficiency may play a rolein the pathogenesis of isoniazid-induced psychosis. Such deficiency states maybe detected indirectly by measuring urinary metabolites of tryptophan.

We performeda retrospective analysis of those patients in the literature and we report acase of isoniazid-induced psychosis in a 42-year-old man with schizophrenia andalcohol dependence. He was abstinent during the last six months.

A 42-year-old man with schizophrenia, in full remission for the last twoyears, presented psychotic symptoms (delusions and hallucinations) suspected tobe related to prophylactic treatment with isoniazid after his brother testedpositive to a tuberculin test. The psychotic symptoms resolved completely afterisoniazid was discontinued. We didn´t change his treatment during the episode(Clopixol 200mg/21 days).

Clinicians should be aware of this adverseeffect of isoniazid and that it may present with a broad clinical picture. As aresult of our findings we coordinated a clinical session with others HospitalDepartments.

1. 1 Isoniazid-Induced Psychosis Ann Pharmacother September 1998 32: 889-891.

2. 2 Vallejo Ruiloba J, Leal Cercos C. Tratado de Psiquiatría. 20. ed. Barcelona: Ars Medica; 2010