Chronic ethanol use in alcoholic beverages by HIV-infected patients affects the therapeutic window of stavudine, lamivudine and nevirapine during the 9-month follow-up period: using chronic alcohol-use biomarkers.

Abstract Background: Chronic ethanol use is a global problem including among HIV-infected patients on stavudine/lamivudine/nevirapine (d4T/3TC/NVP) regimen. The study determined the effect of chronic ethanol use on the therapeutic window of d4T, 3TC and NVP in HIV-infected patients using alcohol-use biomarkers to screen patients for chronic ethanol use. Methods: A case-control study using repeated measures design with serial measurements was used to quantify drugs in plasma. The WHO alcohol use disorder identification test (AUDIT) tool was initially used to screen patients for chronic alcohol use, and then they were further sorted using alcohol-use bioamarkers (γ-glutamyl transferase ≥55.0 IU; mean corpuscular volume, ≥96 fl, aspartate amino transferase/alanine aminotransferase ratio ≥2.0 value). A total of 41 patients (26 in the alcohol group and 15 in the control group) were followed up for 9 months with blood sampling done at 3-month intervals. Plasma drug concentrations were quantified using a Shimadzu Class-VP™ HPLC data system version 6.1. Data was analyzed using SAS 2003 version 9.1 statistical package with repeated measures fixed model. Means were compared using Student's t-test. Results: The mean steady-state plasma drug concentrations of d4T and 3TC in the alcohol group were lower than that in the control group during the 9-month period of follow-up. For 3TC, there was a statistical difference in the mean steady-state plasma drug concentrations between the alcohol group and the control group (p≤0.05) in the 6- and 9-month period of follow-up. For NVP, in both groups they were within the reference ranges, although the drug plasma concentrations were higher in the alcohol group compared to the control group and were statistically significant (p<0.05) in 0, 3 and 6 months of follow-up. Conclusions: Chronic ethanol use by HIV-infected patients reduced the therapeutic steady-state plasma drug concentrations of d4T and 3TC and increased the NVP drug concentrations in the HIV-infected patients.