title: Frequency, types and factors associated with potentially harmful drug interactions in ambulatory elderly patients in Nigeria.
abstract: OBJECTIVE
  To determine the frequency, types and factors associated with potentially harmful drug interactions among ambulatory elderly (≥65 years) patients in Ibadan, Nigeria.
  
  
  METHODS
  A 4-week cross-sectional study was conducted among 229 elderly patients who consented and were prescribed two or more medicines within a 4-week study period at a major 256-bed secondary care facility in Ibadan, Nigeria. Chi-square and risk ratio were used to identify the factors associated with the potentially harmful drug-drug interactions.
  
  
  RESULTS
  Potentially harmful drug-drug interactions were identified in about two-thirds (65%, 149/229) of the patients. The risk of occurrence drug interactions was significantly higher among patients who had at least six prescribed medicines (relative risk: 7.8 (95% confidence interval, 6.9 to 9.5) (P < 0.001)), and a significant majority were also females (73.8%) (110) (P < 0.001). The most frequent interacting drug combination was angiotensin-converting enzyme inhibitors and amiloride + hydrochlorothiazide (34.7%).
  
  
  CONCLUSIONS
  Potentially harmful drug interactions that are significantly associated with high multiple prescribing are considerable among elderly patients in Nigeria.
authors.affiliation: Department of Clinical Pharmacy & Pharmacy Administration, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria.|Department of Pharmacy Practice, College of Clinical Pharmacy, King Faisal University, Hofuf Al-Ahsa, Kingdom of Saudi Arabia.
authors.forename: Kazeem B
authors.initials: KB
authors.lastname: Yusuff
authors.affiliation: Department of Clinical Pharmacy & Pharmacy Administration, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria.
authors.forename: Chinyere Nma
authors.initials: CN
authors.lastname: Okoh
mesh_terms: D000368:Aged; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D009549:Nigeria / Q000453:epidemiology; D012307:Risk Factors
keywords: Nigeria; ambulatory elderly patients; drug interactions