Impact of polypharmacy on antiretroviral prescription in people living with HIV.

OBJECTIVES: To evaluate the relationship between polypharmacy and ART, delivered as conventional multi-tablet three-drug regimens, single-tablet regimens or less-drug regimens (simplified mono or dual regimens). METHODS: We conducted a cross-sectional analysis of electronic data from the prospective Modena HIV Metabolic Clinic Cohort Study. We included the last clinical observation for each patient from January 2006 to December 2015. Polypharmacy was defined as the use of five or more medications (excluding ART). Multi-morbidity was classified as the presence of two or more non-infectious comorbidities. Factors associated with different ART regimens were analysed using multivariable multinomial logistic regression analyses with multi-tablet three-drug regimens as the reference. RESULTS: A total of 2944 patients (33.7% females) were included in the analysis. Multinomial logistic regression analysis identified polypharmacy to be negatively associated with single-tablet regimens [relative risk reduction (RRR) = 0.48, 95% CI = 0.28-0.81] independently from frailty (RRR = 0.68, 95% CI = 0.59-0.78), after correction for age, gender, HIV infection duration, current and nadir CD4 and calendar year. This association was not found comparing multi-tablet three-drug regimens and less-drug regimens. CONCLUSIONS: Single-tablet regimens are less likely to be prescribed in patients with polypharmacy. Single-tablet regimens are perceived to be less flexible in patients with multi-morbidity and at higher risk of drug-drug interaction.