Ethambutol

TREATMENT

Ethambutol (15-25 mg/kg PO q24h or 50-75 mg/kg PO twice a week; maximum, 2.4 g/dose) is bacteriostatic and inhibits arabinosyltransferase (involved in cell wall synthesis). It is commonly utilized in treatment regimens of active TB as well as MAC infections in patients with and without HIV. Doses should be reduced in the presence of renal dysfunction.

SPECIAL CONSIDERATIONS

Adverse events may include optic neuritis, which manifests as decreased red-green color perception, decreased visual acuity, or visual field deficits. Baseline and monthly visual examinations should be performed during therapy. Renal function should also be carefully monitored because drug accumulation in the setting of renal insufficiency can increase risk of ocular effects.