Abstract
Background
Potentially inappropriate prescribing (PIP), potential drug-drug interactions (pDDIs), and elevated medication regimen complexity co-occur frequently in older adults and collectively constitute the "iatrogenic triad" of geriatric pharmacotherapy.Methods
This cross-sectional analytical observational study with prospective recruitment included patients aged 65 years and older attending the Geriatrics Outpatient Clinic. Patients were screened during routine visits using the 2023 American Geriatrics Society Beers Criteria and classified by the presence or absence of at least one PIP. Enrollment continued until 40 patients per group were included; therefore, the study was not designed to estimate PIP prevalence. Clinically significant pDDIs were identified using Micromedex® and UpToDate®. Medication regimen complexity was assessed with the Medication Regimen Complexity Index (MRCI), and independent factors associated with PIP were evaluated using binary logistic regression.Results
Eighty patients were analyzed: 40 with PIP and 40 without PIP. Overall, 48.8% were women, the median age was 71 years (IQR: 67-76), 25% reported a fall within the previous year, and 65% had polypharmacy. Micromedex® detected clinically significant pDDIs in 75% of patients with PIP versus 37.5% without PIP (odds ratio [OR] = 5; p = 0.002) and UpToDate® in 47.5% and 15% (OR = 5.13; p = 0.004). In total, 215 clinically significant pDDIs were identified: 172 major interactions by Micromedex® and 43 D- or X-category interactions by UpToDate®. Total MRCI scores were significantly higher in Group A than in Group B (median 22.8 vs. 15.0; p = 0.005). Polypharmacy (OR = 9.91; p = 0.001) and Anticholinergic Cognitive Burden score (OR = 1.87; p = 0.031) were independently associated with the presence of PIP.Conclusion
In this equal-group outpatient cohort, PIP was associated with higher pDDI burden and greater medication regimen complexity. Polypharmacy and anticholinergic burden were the main modifiable factors associated with PIP. These findings suggest that systematic pharmacist-led medication review may represent a useful strategy for identifying interconnected medication-related risks in geriatric outpatient settings.