Ethambutol‐Induced Optic Neuritis in Patients with End Stage Renal Disease on Hemodialysis: Two Case Reports and Literature Review

Abstract

Ethambutol, a synthetic bacteriostatic agent, is a first line agent against Mycobacterium tuberculosis. Although optic neuritis is the most serious adverse effect of ethambutol, most cases in the literature are reversible. Renal failure prolongs the half‐life of ethambutol and increases the risk of ethambutol‐induced optic neuritis. We present two patients with end stage renal disease (ESRD), who were on maintenance dialysis and suffering ethambutol‐induced optic neuritis. The first woman had been suffering ESRD on hemodialysis for 2 years. After tuberculosis was diagnosed, she was prescribed three‐combined anti‐tuberculosis medications, including ethambutol 800 mg/day. Bilateral blurred vision suddenly occurred 4 months after the start of treatment, and she became totally blind despite discontinuing ethambutol. The second woman had been on hemodialysis for 5 months. Tuberculosis was diagnosed by lung biopsy. After 3 weeks of three‐combined anti‐tuberculosis medications including ethambutol (1200 mg/day), reduced visual acuity and color vision defects occurred. One year after the discontinuation of ethambutol, visual acuity remained little improved. Physicians should be aware of ethambutol‐induced optic neuritis and ethambutol should be used cautiously in patients with renal failure.