title: Identifying and Communicating Clinically Meaningful Drug-Drug Interactions.
abstract: OBJECTIVE
  Providing care to patients with comorbid medical problems may result in complicated, multiple drug therapy regimens, increasing the risk of clinically meaningful drug-drug interactions (DDIs). The purpose of this article is to describe the prevalence of DDIs and provide examples on how to identify and intervene on DDIs.
  
  
  METHODS
  We described DDI data from the Utah Drug Regimen Review Center, where adult Medicaid patients were reviewed by pharmacists from 2005 to 2009. Patients were selected by the number of prescriptions filled per month (>7) or having a high RxRisk score.
  
  
  CONCLUSIONS
  A total of 8860 patients were reviewed, and 16.6% had at least 1 clinically meaningful DDI. Patients with DDIs were slightly younger (mean age 45.2 vs 48.2), more likely to be female (75.0% vs 68.9%), and had more prescriptions per month (13.4 vs 12.5) compared to patients without (P < .001). Pharmacodynamic DDIs were more prevalent (80.2%) than pharmacokinetic. Pharmacodynamic DDIs mainly occurred with drugs used to treat psychiatric/seizure/sleep disorders (69.4%) and pain/migraine (56.6%). Pharmacokinetic DDIs mainly occurred with drugs used to treat psychiatric/seizure/sleep disorders (53.2%), cardiovascular diseases (46.3%), and infectious diseases (29.6%).
  
  
  CONCLUSIONS
  Clinically meaningful DDIs are common in patients with complex medication regimens. A systematic approach for identifying DDIs, determining clinical significance, formulating patient-specific recommendations, and communicating recommendations is important in pharmacy practice.
authors.affiliation: L.S. Skaggs Pharmacy Institute, Department of Pharmacotherapy, University of Utah College of Pharmacy, Salt Lake City, UT, USA scott.nelson@pharm.utah.edu.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Nelson
authors.affiliation: L.S. Skaggs Pharmacy Institute, Department of Pharmacotherapy, University of Utah College of Pharmacy, Salt Lake City, UT, USA.
authors.forename: Joanne
authors.initials: J
authors.lastname: LaFleur
authors.affiliation: L.S. Skaggs Pharmacy Institute, Department of Pharmacotherapy, University of Utah College of Pharmacy, Salt Lake City, UT, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Hunter
authors.affiliation: Utah Medicaid Drug Regimen Review Center, Salt Lake City, UT, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Archer
authors.affiliation: Utah Medicaid Drug Regimen Review Center, Salt Lake City, UT, USA.
authors.forename: Carin
authors.initials: C
authors.lastname: Steinvoort
authors.affiliation: Utah Medicaid Drug Regimen Review Center, Salt Lake City, UT, USA.
authors.forename: CarrieAnn
authors.initials: C
authors.lastname: Maden
authors.affiliation: L.S. Skaggs Pharmacy Institute, Department of Pharmacotherapy, University of Utah College of Pharmacy, Salt Lake City, UT, USA.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Oderda
mesh_terms: D000367:Age Factors; D003157:Community Pharmacy Services; D015897:Comorbidity; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019338:Polypharmacy; D015995:Prevalence; D012737:Sex Factors
keywords: community pharmacy services; drug interactions; pharmacodynamics; pharmacokinetics