Drug Interaction Screening Practices at Hospital Pharmacies in Kwara State

Drug-drug interactions represent a significant cause of preventable adverse drug events in hospitalised patients, and the role of hospital pharmacists in screening for and preventing harmful interactions is a critical patient safety function. This study assessed drug interaction screening practices and pharmacist intervention patterns in hospital pharmacies in Kwara State, North Central Nigeria. A prospective observational study was conducted over four months at four public hospitals in Ilorin, covering the medical, surgical, and elderly care wards. Prescription records were reviewed daily, and potential drug interactions were identified using a validated drug interaction database. Pharmacist interventions and prescriber responses were documented. A total of 1,080 prescriptions containing two or more drugs were reviewed. Potential drug interactions were identified in 24.7 percent of multi-drug prescriptions. Interactions were classified as major in 18.3 percent, moderate in 54.6 percent, and minor in 27.1 percent of cases. The most frequent interacting pairs involved warfarin-NSAIDs, gentamicin-furosemide, and metformin-contrast agents. Pharmacist interventions were delivered for 68.4 percent of identified major interactions, with prescriber acceptance in 81.2 percent of cases. The study concludes that drug interactions are common in Kwara State hospitals and that active pharmacist screening significantly mitigates interaction risks. Formalising daily pharmacist prescription review as standard hospital policy is recommended.

Keywords: drug-drug interactions, prescription screening, hospital pharmacy, Kwara State, patient safety