Cycloserine-Induced Psychosis: A Case Report

Tuberculosis (TB) is a highly infectious disease and a global health challenge caused by Mycobacterium tuberculosis. The disease presents as drug-sensitive TB or drug-resistant TB (DR-TB). DR-TB could be of various types like isoniazid mono-resistant, multidrug-resistant (MDR)-rifampicin mono-resistant (MDR-RR), MDR-TB, extensively DR-TB (XDR-TB), or pre-XDR-TB. Management of DR-TB is challenging due to the longer treatment duration and adverse drug reactions (ADRs) to the second-line anti-TB drugs. Some of these could be life-threatening and require urgent care. Neuropsychiatric ADRs associated with cycloserine require greater attention due to their potential to cause treatment failure. The objective of this case report is to emphasize the importance of awareness about psychiatric ADRs caused by antitubercular agents. It also highlights the reversible nature of these adverse events upon drug withdrawal. To ensure methodological rigor in the assessment of psychosis, the Brief Psychiatric Rating Scale (BPRS) and Naranjo ADR Probability Scale were employed as diagnostic tools to evaluate the severity of psychiatric symptoms and establish the likelihood of an ADR, respectively. It is emphasized here that proper vigilance with immediate management is essential to avoid fatal outcomes. Herein, a case of ADR caused by cycloserine in a pulmonary MDR-TB case as a part of a new modified longer regimen in the Department of Respiratory Medicine at Shri B M Patil Medical College, Hospital and Research Centre, Vijayapura, Karnataka, is presented.