Drug Prescribing Patterns and Potential Drug-Drug Interactions in Elderly Patients Admitted to Medicine Wards at Aminu Kano Teaching Hospital, Kano State

Elderly patients admitted to medicine wards are at heightened risk of clinically significant drug-drug interactions due to the prevalence of multiple comorbidities, complex polypharmacy regimens, and age-related pharmacokinetic changes. This study analyzed drug prescribing patterns and potential drug-drug interactions among elderly inpatients at Aminu Kano Teaching Hospital, Kano State, North West Nigeria. A cross-sectional retrospective study reviewed 300 randomly selected case records of patients aged 65 years and above admitted to the internal medicine ward over a 24-month period. Drug-drug interaction analysis was conducted using the Lexicomp drug interaction database and Micromedex, and interactions were classified by severity. The mean number of drugs per admission was 7.3. At least one potential drug-drug interaction was identified in 72 percent of patients. Clinically significant drug-drug interactions of moderate or major severity were detected in 58 percent. The most common interactions involved digoxin-furosemide, aspirin-warfarin, and aminoglycoside-loop diuretic combinations. Polypharmacy with more than eight medications was the strongest predictor of multiple drug-drug interaction risk. Pharmacist input in prescription review was documented in only 12 percent of cases. These findings highlight a high and preventable burden of drug-drug interaction risk in this population. Mandatory pharmacist-led medication review and drug-drug interaction screening for all elderly inpatients at Aminu Kano Teaching Hospital are recommended as immediate safety priorities. Keywords: drug-drug interactions, elderly patients, polypharmacy, Aminu Kano Teaching Hospital, medication safety