Accumulation of HIV-1 Drug Resistance Mutations and Methamphetamine Use

Background: Antiretroviral therapy (ART) non-adherence and methamphetamine use are associated with higher HIV drug resistance prevalence. How they affect drug resistance mutations accumulation is less studied. Objective: We assessed factors associated with drug resistance mutations accumulation. Methods: We evaluated HIV chronically-infected patients from a clinic-based research cohort on first-line ART regimens with genotype results within 30 days of baseline. Methamphetamine use and ART adherence were self-reported at each study visit. High ART adherence was defined as 0-5% missed doses in the last 30 days. Results: One-hundred twenty-five patients contributed 496 study visits. At baseline, 81% of patients reported high ART adherence; 90% reported no methamphetamine use in the prior 4 months, 8% used monthly or less and 2% used daily or weekly. Methamphetamine users and non-users had similarly high ART adherence (p=0.93). Adjusted incidence rate ratio (aIRR) of drug resistance mutations accumulation was 2.04 (95% CI 0.64, 6.46) for daily/weekly users and 1.71 (95% CI 0.66, 4.42) for patients with monthly or less users, compared to non-users. aIRR was 0.71 (95% CI 0.44, 1.15) with >5-10% missed ART doses and 1.21 (95% CI 0.80, 1.83) with >10% missed doses compared to 0-5% missed doses. Conclusion: We found no strong evidence for the effect of methamphetamine use and ART adherence on drug resistance mutations accumulation. Research cohort patients may have been more engaged in care and treatment adherent than non-cohort patients. Our findings suggest methamphetamine use might not lead to treatment failure among HIV patients who are otherwise engaged in care.