Medication Burden and Clustering in People Living with HIV Undergoing Therapeutic Drug Monitoring

AIM: People living with HIV (PLWH) have a high burden of comorbidities and concomitant medication use. Aim of this study was to analyze the prevalence, predictors and patterns of polypharmacy (PP) in a large therapeutic drug monitoring (TDM) registry.METHODS: We searched our TDM registry and categorized co-medications into 26 drug classes. We included patients with at least one medication recorded: PP and severe PP (sPP) were defined as the concomitant use of ≥5 or ≥10 non-antiretroviral/non-antitubercular drugs. Multivariable binary logistic analysis were conducted for identifying PP/sPP predictors. A hierarchical average-linkage cluster analysis was performed among drug classes.RESULTS: We included 2432 participants (1158 PLWH) aged 49.6 years (± 14.4) in the 2016-2020 period. A higher number of concomitant medications (4 vs. 3.1, p<0.001) and a higher prevalence of PP (26.1% vs. 21.8%, p=0.015) were recorded in controls. At multivariable binary logistic analysis older age, female gender and HIV-positive serostatus (p=0.015) were independent predictors of PP; older age and year of inclusion were independent predictors of sPP. Cluster analysis showed that patients receiving oral drug for type-2-diabetes have a high probability of receiving several other drugs; a cluster of co-medications was observed with opioids, diuretics and central nervous system affecting drugs.CONCLUSION: We observed a moderately high prevalence of polypharmacy in middle-aged PLWH: advanced age and female gender were associated with the greatest prevalence. The observation of co-medication clusters suggests groups of comorbidities but also identifies groups of patients at risk of similar drug to drug interactions.