Pre-admission Administration of Inappropriate Medications in Geriatric Patients Admitted to a Tertiary Care Teaching Hospital

Background: The global population of older adults is on the rise. Considering differences in the pharmacokinetics and pharmacodynamics of medications in this population, some medications are considered potentially inappropriate. This study examines the pre-admission use of potentially inappropriate medications (PIM) in hospitalized geriatric patients and investigates drug-drug interactions (DDI) among these individuals. Methods: This cross-sectional study was conducted at a tertiary care teaching hospital in Tehran, Iran. The Beers criteria were utilized to identify potentially inappropriate medications (PIMs). All medications taken prior to admission, including over-the-counter drugs, herbal remedies, and dietary supplements, were documented along with the patients' diseases and health conditions. Results: Among the patients, 56.8% were men, and their ages ranged from 65 to 95 years. We found that 39% of patients received at least one PIM. Out of 1406 pre-admission medications, 132 (9.3%) and 26 (1.84%) were classified as potentially inappropriate medications (PIM) based on drug-to-avoid and drug-disease criteria, respectively. In 4.4% of patients, selected DDI was noted, and polypharmacy was observed in 151 (60.4%) patients. The most frequent PIM in drug-to-avoid criteria belonged to the nervous system (46.46%), followed by the gastrointestinal system and metabolism (26.1%). Based on the drug-to-avoid and drug-disease criteria, the average number of underlying diseases in patients with PIM was significantly higher than those without PIM (p-value = 0.014 and p-value = 0.001, respectively). Conclusion: The prevalence of PIM in the present study was similar to that of previous studies conducted with the same criteria and setting. Polypharmacy and a higher number of comorbidities significantly increased PIM utilization. With the growing elderly population, healthcare providers must be more vigilant about the varied medication needs of this population.