The Impact of Non-Antiretroviral Polypharmacy on the Continuity of Antiretroviral Therapy (ART) Among HIV Patients

Improved survival achieved by many patients with HIV/AIDS has complicated their medical care as increasing numbers of co-morbidities leads to polypharmacy, increased pill burdens, and greater risks of drug-drug interactions potentially compromising antiretroviral treatment (ART). We examined the impact of non-antiretroviral polypharmacy on ART for all adults followed at the Southern Alberta Clinic, Calgary, Canada. Polypharmacy was defined as 5 daily medications. We compared the impact of polypharmacy on continuous (i.e., remaining on same ART for 6 months) vs. non-continuous (i.e., discontinuing or switching ART) ART dosing frequency, number of ART pills, number of non-ART medications, and age. Of 1190 (89.5%) patients on ART, 95% were on three-drug regimens, 63.9% on QD ART, and 62% 3 ART pills daily; 32.2% were experiencing polypharmacy. Polypharmacy was associated with lower CD4, AIDS, >180 months living with HIV, higher numbers of ART pills, and older age (all p<0.01); 32.1% stopped or switched ART. Polypharmacy increased the risk for non-continuous ART (36.8% vs. 30.0%; p<0.01). Non-continuous ART increased with daily ART pill count but not increased age. Non-adherence and adverse effects accounted for the majority of non-continuous ART. We found a strong association between polypharmacy and non-continuous ART, potentially leading to effective ART being compromised. Collaborative approaches are needed to anticipate the negative impacts of polypharmacy.