Retreatment with Ethambutol After Toxic Optic Neuropathy (.pdf)

"Ethambutol is an important component of the treatment for mycobacterial infections. Toxic optic neuropathy is a dose-dependent side effect of ethambutol treatment, occurring in approximately 5-6% of patients at 25mg/kg/day and in 1% at 15mg/kg/day. When optic neuropathy is suspected, ethambutol is typically withdrawn. Some patients require retreatment for mycobacterial infections, but the safety of ethambutol retreatment in a patient who previously developed and recovered from ethambutol-induced optic neuropathy or chiasmopathy has not been established."