Ethambutol Induced Optic Neuritis Associated with Tenofovir Nephrotoxicity

Morbidity and mortality associated with human immunodeficiency virus (HIV) has decreased with highly active anti-retroviral therapy (HAART). Tenofovir is a nucleotide reverse transcriptase inhibitor (NRTI) that is preferred by the Department of Health and Human Services (DHHS) HIV treatment guidelines and is widely used for the initial treatment of HIV. Although tenofovir is generally well-tolerated, it has been associated with rare cases of acute nephrotoxicity. HIV-infected patients frequently have co-morbidities that require treatment, thus adding another level of complexity due to drug interactions and medication adverse effects with antiretrovirals. We present a patient who suffered an acute deterioration in renal function from tenofovir, leading to an accumulation of co-administered ethambutol, thus resulting in optic neuritis.