Alcohol Drinkers' Exposure to Preventive Therapy for TB (ADEPTT)

Overview

The Alcohol Drinkers' Exposure to Preventive Therapy for TB (ADEPTT) will examine the safety and tolerability of, and adherence to, 6 months of daily INH (6H) in 300 TB and HIV-infected persons (200 drinkers and 100 non-drinkers) in Uganda. The first aim is to evaluate the safety and tolerability of 6H overall and by level of alcohol use. The second aim is to estimate adherence and compare adherence by level of alcohol use and at 3 and 6 months. Self-reported measures of alcohol use will be augmented by phosphatidylethanol (PEth), an established biomarker of alcohol use. Objective measures of adherence will include electronic pill bottle monitoring and a novel measure of INH exposure, INH concentration in hair. The study will actively monitor for hepatotoxicity using the U.S. standard of care for TB preventive therapy for heavy drinkers and discontinue if any Grade 3/4 toxicities are detected. The investigators will use the safety, tolerability, and adherence results, together with the known efficacy and mortality benefit of TB preventive therapy in HIV-infected persons in SSA, and an established decision analytic model of TB preventive therapy to conduct the third aim: to determine whether the benefits of TB preventive therapy outweigh the toxicity risks for HIV-infected drinkers in resource limited settings. The study will additionally follow the cohort every 6 months after completing INH to monitor drinking and the development of active TB.

Tuberculosis (TB) is the leading cause of mortality in persons with HIV worldwide, accounting for 20-33% of HIV-related deaths, and is a high-priority area of research in HIV/AIDS by the NIH. TB preventive therapy decreases both all-cause mortality and active TB in persons with HIV by 30-50% above and beyond the benefits of antiretroviral therapy (ART) alone. Based on these findings, the World Health Organization (WHO) recommends isoniazid (INH) preventive therapy (IPT) for all persons with HIV in resource constrained settings. However, the WHO warns against the use of IPT in persons with "regular and heavy alcohol use." This exclusion stems from concern for increased hepatotoxicity in heavy drinkers in settings where liver enzymes are not routinely monitored. Heavy drinking in persons with HIV is very common, approximately 25%, in sub-Saharan Africa (SSA). Heavy drinking increases the risk for active TB at least threefold; thus, HIV-infected alcohol users should be prioritized for TB prevention. However, no studies have systematically assessed the safety of TB preventive therapy in heavy drinkers with or without HIV infection. It is critical to examine the safety and tolerability of TB preventive therapy for HIV-infected drinkers, given the high rates of HIV, TB infection, and alcohol comorbidities worldwide. While the risk of toxicity exists, the risk of TB disease could outweigh the toxicity harms. Thus, it is also crucial to determine whether the mortality benefits outweigh the toxicity risks for this significant portion of the HIV-infected population. In addition, TB preventive therapy is only effective if taken consistently for the full course. Alcohol use is an established risk factor for decreased ART pill taking and active TB treatment discontinuation. Whether HIV-infected drinkers on ART can be adherent to TB preventive therapy is not known. Therefore it is essential to determine the level of adherence to TB preventive therapy by HIV-infected drinkers on ART, thus this study aims to examine adherence to TB preventative therapy as well. This is a study to examine 6 months of daily INH (6H) among N=300 persons co-infected with HIV and TB. The aims of the study are: Aim 1: To examine the safety and tolerability of 6H in HIV/TB co-infected drinkers, measured by hepatotoxicity and treatment discontinuation rates. The main aim is to estimate safety and tolerability overall among drinkers (primary) and by level of drinking (secondary). Aim 2: To determine the level of TB preventive therapy adherence overall among drinkers and by level of drinking, and at 3 and 6 months. The main goal of this aim is to estimate adherence overall among drinkers (primary). Secondarily the investigators will estimate adherence by level of drinking (heavy, current but not heavy drinkers, and non-drinkers) and compare adherence across drinking levels. The investigators hypothesize that adherence will be highest among the non-drinkers. Aim 3: To determine whether the benefits of providing TB preventive therapy to HIV-infected drinkers in resource-limited settings outweigh the risks compared to no treatment. The investigators hypothesize that providing TB preventive therapy will result in longer life expectancy and quality-adjusted life expectancy than not providing TB preventive therapy (current standard of care).