Potential drug-drug interactions and clinical outcomes among people living with HIV with comorbidities: A multicentre retrospective cohort study.

AIMS: This study aimed to determine the prevalence and patterns of potential drug-drug interactions (pDDIs), identify associated factors among people living with HIV (PLWH) with comorbidities and examine associations with clinical outcomes. METHODS: This multicentre retrospective study was conducted across three healthcare tiers in Thailand during 2023-2024. pDDIs were identified using Lexicomp (categories A-X). Multivariable logistic regression identified factors associated with pDDIs and assessed associations with viral suppression (viral load <50 copies/mL) and treatment target achievement. RESULTS: Among 1791 PLWH (median age 50.5 years, 50.6% female; median 3 comorbidities, 8 medications; 93.9% virally suppressed), 30.0% had at least one pDDI. Analysis of 9338 prescriptions showed a pDDI rate of 30.2 per 100 prescriptions (category C: 20.7; D: 5.6; B: 3.2; X: 0.7). Significant predictors of pDDIs included protease inhibitor-based regimens (vs. integrase strand transfer inhibitor-based regimens; aOR 12.61; 95% CI 7.45-21.34), diabetes mellitus (aOR 6.70; 95% CI 4.30-10.45) and management at general hospitals (vs. tertiary centres; aOR 1.89; 95% CI 1.20-3.00). Female sex was independently associated with high-severity (category D/X) interactions (aOR 1.50; 95% CI 1.09-2.06). Furthermore, the presence of any pDDI was significantly associated with lower odds of viral suppression (aOR 0.52; 95% CI 0.28-0.98). CONCLUSIONS: pDDIs remain common among PLWH with comorbidities, particularly in those receiving protease inhibitor-based regimens, those with diabetes mellitus and those managed in general hospitals. Their association with lower odds of viral suppression highlights the importance of careful antiretroviral selection, routine medication review and integrated multidisciplinary care.