Safety and tolerability of isoniazid preventive therapy for tuberculosis for persons with HIV with and without alcohol use

Isoniazid (INH) preventive therapy is recommended to prevent tuberculosis (TB) disease for persons with HIV (PWH), except for those with regular and heavy alcohol consumption, due to hepatotoxicity concerns. We aimed to quantify the incidence of severe INH-related toxicity among PWH with and without recent alcohol consumption.A prospective study of PWH receiving INH.We included PWH in southwest Uganda with recent (prior 3 months) ( n = 200) or no (prior year) self-reported alcohol consumption ( n = 101), on antiretroviral therapy, TB infected (≥5 mm on tuberculin skin test), and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) 2× or less the upper limit of normal (ULN). Grade 3+ INH-related toxicity was ALT or AST at least 5× the ULN or severe symptoms; we stopped IPT upon detection. Grade 2 INH-related toxicity was ALT or AST 2-5× the ULN or moderate symptoms.The cumulative incidence of Grade 3+ INH-related toxicity was 8.3% [95% confidence interval (95% CI) 5.4-12.0]; all resolved after INH cessation. Incidence was 6.0% (95% CI 3.1-10.2) among those reporting recent alcohol use and 12.9% (95% CI 7.0-21.0) among those reporting no prior year alcohol use. We found no differences by baseline phosphatidylethanol-confirmed alcohol severity. The cumulative incidence of Grade 2 toxicities (without Grade 3+) was 21.7% (95% CI 17.0-27.1); 25.0% (95% CI 19.0-31.8) among those with recent alcohol use and 14.8% (95% CI 8.1-23.9) among those with no prior year alcohol use.Alcohol use does not appear to increase risk for serious INH-related toxicity among PWH without significant liver enzyme elevations at baseline (≤2x ULN).