Toddler With Intermittent Abnormal Behavior: Is It Isoniazid-Induced Psychosis?

Abstract Psychosis is a state of altered behavior and mentation, and it is rarely reported in preschool children. Isoniazid is a commonly used drug in the treatment and prophylaxis of tuberculosis. It may cause psychosis in overdose but rarely with usual recommended doses. We report a case of drug-induced psychosis secondary to isoniazid intake in a 3-year-old child. She developed intermittent abnormal behavior for 2 weeks after intake of isoniazid. Drug-induced psychosis was a possibility, and the responsible drug was stopped. She improved following the withdrawal of isoniazid.