Polypharmacy, potentially serious clinically relevant drug-drug interactions, and inappropriate medicines in elderly people with type 2 diabetes and their impact on quality of life.

The aim of the study is to investigate the patterns of polypharmacy, clinical-relevant drug-drug interactions (DDIs), and potentially inappropriate medicines (PIMs), and whether polypharmacy, potential serious clinically-relevant DDIs, or PIMs can be associated with low quality of life (QoL) index scores of older adults with type 2 diabetes (T2D). A cross-sectional study was conducted using data of 670 elderly T2D sub-cohort from a nationwide pharmacy-based intensive monitoring study of inception cohort of T2D in Portugal. 72.09% were found on polypharmacy (≥5 medicines). Participants on polypharmacy were mostly females (P = .0115); more obese (P = .0131); have more comorbid conditions (P < .0001); more diabetes complications (P < .0001); and use more of glucose lowering drugs (P = .0326); insulin (P < .0001); chronic medicines (P < .0001); and have higher diabetes duration (P = .0088) than those without polypharmacy. 10.59% of the participants were found to have potential serious clinically relevant DDIs. The most frequent drug-combinations were angiotensin-converting enzyme (ACE) inhibitors with angiotensin-receptor blockers (ARBs), aspirin with Selective serotonin reuptake inhibitors (SSRIs), and clopidogrel with calcium channel blockers. PIMs are found in 36.11% of the participants. The most common PIMs were benzodiazepines, long-acting sulfonylureas, and iron overdose. The adjusted multivariate models show that Polypharmacy, PIMs, and potential serious clinically relevant DDIs were associated with lower QoL index scores (OR 1.80 95% CI 1.15-2.82), (OR 1.57 95% CI 1.07-2.28), and (OR 1.34 95% CI 0.73-2.48) respectively. The study shows that polypharmacy, potential serious clinical-relevant DDIs, and PIMs may correlate with risk of reduced health related QoL outcome of older adults with T2D.