A Case of Isoniazid-Induced Optic Neuropathy

Watana Navacharoen M.D.
Department of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai.

    Abstract A case of pulmonary tuberculosis which developed anterior optic neuropathy 6 months after recieved isonizid 300 mg/d, pyridoxine 25 mg/d, ethambutal 800 mg/d and rifampin 600 mg/d. Ethambutal was discontinued but the visual acuity were progressively worse. Two months later isoniazid was also discontinued and visual acuity gradually improved in 1 month follow up.

    In tuberculosis patients treated with both ethambutal and isoniazid, physicians should keep in minds that both may produce a toxic optic neuropathy. If improvement in acuity does not occur when one of the agents is discontinued in a period of time, the other should be discontinued as well. 

Thai J Ophthalmol 1988; March 2(1):12-14.