P-225. Polypharmacy, Drug-Drug Interactions, and Risk of Hospitalization among Veterans with HIV Taking 2-, 3-, and 4-Drug Antiretroviral Therapy Regimens

Abstract Background As people with HIV (PWH) age while on antiretrovirals (ARVs), they experience greater non-ARV polypharmacy, increasing their risk of drug-drug interactions. Using data on PWH in the Veterans Aging Cohort Study (VACS) in the US, we assessed whether non-ARV medication count and overlapping prescriptions with known pairwise drug interactions (KPDIs) were associated with risk of hospitalization. Methods We included PWH enrolled in the VACS taking 2-drug ARV regimens 2DR; dolutegravir/lamivudine (DTG/3TC), dolutegravir/rilpivirine (DTG/RPV), 3DR (integrase inhibitor, protease inhibitor, or non-nucleoside reverse transcriptase inhibitor with 2 nucleoside reverse transcriptase inhibitors), or 4DR (3DR plus cobicistat or ritonavir) between 01OCT2020 and 30SEP2023. Pharmacy fill records were used to identify all non-ARV prescriptions overlapping during the course of the baseline ARV regimen. Pairs of medications with KPDI were identified from the DrugBank database. We constructed an exposure-weighted KPDI Index using the average association of each identified KPDI with 1-year mortality. We used nested Cox models to estimate the association between non-ARV medication count and 1-year risk of hospitalization, adjusting for KPDI Index. Results The analysis included 20,661 PWH (DTG/3TC: 661, DTG/RPV: 866, 3DR: 15,920, 4DR: 3,214), with 97% male, 36% White, 48% Black, and 11% Hispanic Table 1. Those on DTG/RPV were older, had more comorbidities, and higher VACS Index 2.0 scores. Median IQR non-ARV medication count ranged from 4 2, 9 for 4DR to 6 3, 10 for DTG/RPV. Median KPDI Index ranged from 0.26 -1.07 to 2.69 for DTG/3TC to 1.81 -0.54 to 8.11 for 4DR. Higher non-ARV medication count was associated with increased risk of hospitalization regardless of ARV regimen, and adjusting for demographics, frailty, and KPDI Index reduced these associations Table 2. Generally, those with higher KPDI Index had greater risk of hospitalization. Conclusion The association between increasing non-ARV medication count and risk of hospitalization may be partially explained by drug-drug interactions. Disclosures Cassidy Henegar, PhD, MSPH, ViiV Healthcare: Employee|ViiV Healthcare: Stocks/Bonds (Public Company) Vincent Marconi, MD, Lilly: Grant/Research Support|Merck: Grant/Research Support Leigh Ragone, MS, GSK: Stocks/Bonds (Private Company)|ViiV Healthcare: Employee Bryn Jones, MBChB, GSK: Stocks/Bonds (Public Company)|ViiV Healthcare: Employee Vani Vannappagari, MBBS, MPH, PhD, ViiV Healthcare: Full time Employee of ViiV Healthcare and owns GSK stock|ViiV Healthcare: Stocks/Bonds (Public Company)