An Evaluation of Potential Inappropriate Prescribing Among Older Persons in Nigeria

Potential Inappropriate prescribing (PIP), Drug-Drug interactions (DDI) and polypharmacy are major risk factors for adverse drug reactions among older persons. Although these factors in many cases co-exist in prescriptions to older persons, very few studies have evaluated the inter-relationship between these factors concomitantly. This study aimed to evaluate PIP and DDI and to determine the associations between PIP, DDI, and polypharmacy among Nigerian older persons. This study was a retrospective evaluation of medicine utilization among older persons at Olabisi Onabanjo University Teaching Hospital, Nigeria, using a medical chart review. Older persons aged ≥60 years, with chronic diseases that attended the medical outpatient clinics of the hospital between 1st January and 31st December 2016 were included. Eligible patients’ records were randomly sampled. Information including patients’ demographics, medical and medication histories and current medications were extracted with a checklist. PIP and DDI were evaluated using the 2015 updated Beers Criteria. Associations were determined using Chi-squared test and a binary logistic regression. A total of 352 participants, mean age 69.03±7.35 years were evaluated. According to the Beers Criteria, PIP and DDI among the participants were (124/352, 35.2%) and (20/352, 5.7%) respectively. Majority of the participants (192/352, 54.5%) received polypharmacy. A few participants (12/352. 3.4%) received prescriptions containing PIP, DDI, and polypharmacy concomitantly. DDI was significantly associated with PIP in a logistic regression (OR=0.18, 95%CI=0.05-0.68, p=0.01) and with polypharmacy in a Chi-squared test (OR=3.55, 95%CI=1.16-10.83, p=0.02). This study concludes that PIP, DDI and polypharmacy are interrelated and should be considered when prescribing to older persons.