title: Potential drug-drug interactions in internal medicine wards in hospital setting in Pakistan.
abstract: BACKGROUND
  Multiple drugs therapies may be the potential source of drug-drug interactions that can result in alteration of therapeutic response and/or increase untoward effects of many drugs.
  
  
  OBJECTIVE
  To identify the frequency and levels of potential drug-drug interactions (pDDIs) in internal medicine wards and their association with patients' age, gender, length of hospital stay and number of prescribed medications; and to describe management of frequently identified major or moderate pDDIs.
  
  
  METHODS
  Internal medicine wards of two major tertiary care hospitals of Khyber Pakhtunkhwa, Pakistan.
  
  
  METHODS
  Micromedex Drug-Reax system was used to screen patient's profiles for pDDIs. Logistic regression was applied to determine the odds ratio for specific risk factors of pDDIs i.e., age, gender, hospital-stay and number of medications.
  
  
  METHODS
  Overall prevalence and prevalence of contraindicated, major, moderate and minor pDDIs; levels of pDDIs; frequently identified major or moderate interactions; and odds ratios for risk factors.
  
  
  RESULTS
  Total, 188 interacting drug-combinations were identified that contributed to 675 pDDIs. Of 400 patients, 52.8% patients were presented with at least one pDDI (overall prevalence), 21.3% with at least one major-pDDI, and 44.3% with at least one moderate-pDDI. Of 675 pDDIs, most were of moderate (63.6%) or major severity (23%); good (61.2%) or fair (25.5%) type of scientific evidence; and delayed onset (50.2%). Most frequently identified major or moderate interactions resulted in 45.3% of all pDDIs. Their potential adverse outcomes included hepatotoxicity, bleeding, ototoxicity, nephrotoxicity, hypoglycemia, hyperglycemia, risk of thrombosis, hypotension, cardiac arrhythmias and reduction in therapeutic-effectiveness. There was significant association of the occurrence of pDDIs with patients' age of 60 years or more (OR = 2.1; 95% CI = 1.3-3.3; p = 0.003), hospital stay of 6 days or longer (OR = 2.6; 95% CI = 1.5-4.5; p = 0.001), and seven or more number of prescribed medications (OR = 5.9; 95% CI = 3.6-9.6; p < 0.001).
  
  
  CONCLUSIONS
  The present study has recorded a high prevalence of pDDIs in internal medicine wards. Patients with old age, longer hospital stay and increased number of prescribed medications were at higher risk.
authors.affiliation: Department of Pharmacy, University of Peshawar, Peshawar, Khyber Pakhtunkhwa, Pakistan.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ismail
authors.forename: Zafar
authors.initials: Z
authors.lastname: Iqbal
authors.forename: Muhammad Bilal
authors.initials: MB
authors.lastname: Khattak
authors.forename: Muhammad Imran
authors.initials: MI
authors.lastname: Khan
authors.forename: Hassan
authors.initials: H
authors.lastname: Arsalan
authors.forename: Arshad
authors.initials: A
authors.lastname: Javaid
authors.forename: Qamar
authors.initials: Q
authors.lastname: Gul
authors.forename: Faramoz
authors.initials: F
authors.lastname: Khan
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D005260:Female; D006748:Hospital Departments; D006801:Humans; D007388:Internal Medicine; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010154:Pakistan; D055553:Prescription Drugs / Q000008:administration & dosage / Q000009:adverse effects*; D015995:Prevalence; D012307:Risk Factors; D055815:Young Adult
chemical_list: D055553:Prescription Drugs