Prolonged isoniazid-induced psychosis in a patient on DOTS therapy – A case report

Isoniazid is the first line drug for the treatment of tuberculosis in comparison to all anti- tubercular agents. This potent drug is economical and less toxic. The common side effects are rash, hepatitis, peripheral neuropathy, tinnitus and SLE. The less frequent but serious neurological adverse effect which has been reported with INH is psychosis. We hereby report a case of 24 years old female patient with complaints of fever, generalized weakness and swelling in the neck. She was under pulmonary tuberculosis treatment with isoniazid, rifampicin, pyrazinamide and ethambutol for three months. According to her caregivers she complained of behavioral disturbance, talking to her own and refusal to take food since one month. She was diagnosed with psychosis; characterized with catatonia and sleep disturbance. Oralolanzapine 1mg twice daily and orallorazepam 10mg once daily was initiated following which her symptoms improved in 23 days. The mechanism for INH induced psychosis is not clearly understood. It is usually treated by the cessation of INH or with antipsychotics. Its combination can be given based on the severity of psychosis. The most challenging aspect is such patients’ is the re-initiation of INH. This case report concluded that with prompt diagnosis and management of psychosis, INH can be successfully re- challenged in serious cases also.