Munsami, LyneshreeSchutte, Clara-MariaDe Villiers, MarykeHiesgen, Juliane2024-01-262024-01-262023-01-19Munsami, L., Schutte, C.M., De Villiers, M. & Hiesgen. J. Late-onset efavirenz toxicity: A descriptive study from Pretoria, South Africa. Southern African Journal of HIV Medicine 2023;24(1), a1439. https://DOI.org/10.4102/sajhivmed.v24i1.1439.1608-9693 (print)2078-6751 (online)10.4102/sajhivmed.v24i1.1439http://hdl.handle.net/2263/94121DATA AVAILABILITY : The data that support the findings of this study are available from the corresponding author, J.H., upon reasonable request.BACKGROUND : The neuropsychiatric side effects of efavirenz occur mainly early during treatment and are usually mild. A lesser-known and serious complication is late-onset efavirenz toxicity causing ataxia and encephalopathy. Data regarding this condition are limited. OBJECTIVES : We describe the clinical picture of late-onset efavirenz toxicity, investigate co-morbidities and report outcomes. METHOD : This descriptive study of all patients with late-onset efavirenz toxicity was conducted over three years at Kalafong Provincial Tertiary Hospital, Pretoria, South Africa. RESULTS : Forty consecutive patients were identified. Mean age was 42.1 years, three patients (7.5%) were male and the mean efavirenz level was 49.0 μg/mL (standard deviation [s.d.]: 24.8). Cerebellar ataxia (82.5%) and encephalopathy (47.5%) were the most common presenting features (40.0% had both); four patients presented with psychosis. Presence of encephalopathy and/or cerebellar ataxia was associated with higher efavirenz levels compared with psychosis (52.1 μg/mL, s.d.: 24.1 vs 25.0 μg/mL, s.d.: 17.1). In most patients, symptoms resolved, but four patients (10.0%) died, and one patient remained ataxic. CONCLUSION : Late-onset efavirenz toxicity typically presented with ataxia and encephalopathy, but psychosis can be the presenting feature. The outcome after withdrawal was good, but the mortality of 10.0% is concerning. Recent changes in guidelines favour dolutegravir, but many patients remain on efavirenz, and awareness of the condition is vital. WHAT THIS STUDY ADDS : This large, single-centre study contributes to the limited data of HIV-positive patients with late-onset efavirenz toxicity and emphasises its ongoing relevance in clinical practice.en© 2023. The Authors. Licensee: AOSIS. This work is licensed under the Creative Commons Attribution License.Efavirenz toxicityAtaxiaEncephalopathyPsychosisHuman immunodeficiency virus (HIV)SDG-03: Good health and well-beingHealth sciences articles SDG-03SDG-03: Good health and well-beingArticle