title: Potential drug-drug interactions in prescriptions dispensed in community pharmacies in Greece.
abstract: OBJECTIVE
  To evaluate the nature, type and prevalence of potential drug-drug interactions (DDIs) in prescriptions dispensed in community pharmacies in Thessaloniki, Greece. Secondary objectives included the classification of DDIs as per pharmacotherapeutic class of the medications and the investigation of the relationship between medical specialties and the frequency of potential DDIs, as well as the relationship between DDIs and prescription size. Setting DDIs are a common cause of adverse drug reactions (ADRs) among patients using multiple drug therapy. In Greece a reliable computerized surveillance system for monitoring potential DDIs is not yet fully established. As a result, the prevalence of such DDIs in prescriptions dispensed by community pharmacies in Greece is unknown.
  
  
  METHODS
  We conducted a prospective, descriptive study. Over a 3-month period (November 2007-January 2008), a total of 1,553 handwritten prescriptions were collected from three community pharmacies in Thessaloniki, Greece. The prescriptions were processed using the Drug Interactions Checker within the www.drugs.com database. The identified potential DDIs were categorized into two classes, major and moderate, according to their level of clinical significance.
  
  
  METHODS
  Overall 213 prescriptions had one or more potential DDIs and a total of 287 major and moderate DDIs were identified. Potential DDIs were identified in 18.5% of all prescriptions. Major DDIs were identified in 1.9% of all prescriptions and represented 10.5% of all DDIs detected, whereas moderate DDIs were identified in 16.6% of all prescriptions and represented 89.5% of all DDIs detected. The rate of DDIs increased with prescription size. The most common drug involved in major DDIs was amiodarone which interacts with potassium-wasting diuretics, digoxin, simvastatin and acenocoumarol.
  
  
  CONCLUSIONS
  Our results indicate that patients in Greece are at risk of ADRs caused by medications due to potential DDIs. An appropriate surveillance system for monitoring such interactions should be implemented and physicians should be more aware of potentially harmful DDIs. Pharmacists can contribute to the detection and prevention of drug-related injuries, especially of clinically meaningful DDIs that pose a potential risk to patient safety.
authors.affiliation: Department of Pharmacy, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Chatsisvili
authors.forename: Ioakeim
authors.initials: I
authors.lastname: Sapounidis
authors.forename: Georgia
authors.initials: G
authors.lastname: Pavlidou
authors.forename: Eudoxia
authors.initials: E
authors.lastname: Zoumpouridou
authors.forename: Vasileios-Alexandros
authors.initials: VA
authors.lastname: Karakousis
authors.forename: Marios
authors.initials: M
authors.lastname: Spanakis
authors.forename: Lefteris
authors.initials: L
authors.lastname: Teperikidis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Niopas
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D003157:Community Pharmacy Services / Q000706:statistics & numerical data*; D004347:Drug Interactions; D006115:Greece; D006302:Health Services Research; D006801:Humans; D055553:Prescription Drugs / Q000009:adverse effects*; D011446:Prospective Studies
chemical_list: D055553:Prescription Drugs