title: How many potential drug-drug interactions cause adverse drug reactions in hospitalized patients?
abstract: BACKGROUND
  Potential drug-drug interactions (DDIs) are frequent in drug prescription but clinically significant are the ones which can result in changes of therapeutic effect of one of the two drugs or in adverse drug reactions (ADRs). The aim of this study was to assess the potential DDIs as well as the DDIs which cause adverse drug reactions (ADRs) in an internal medicine department hospitalized patients.
  
  
  METHODS
  The prospective study included all patients admitted between November 2010 and January 2011 in an internal medicine ward. Information on patients' demographics and their medication use history was obtained from each patient by interview. In addition, medical history, medication use during hospitalization, and relevant laboratory and clinical data were obtained from medical records. Potential DDIs were identified using the Thomson Micromedex program. Each patient was monitored during the hospitalization period in order to detect the ADRs resulting from DDI's if present.
  
  
  RESULTS
  Three hundred and five patients were enrolled in this study during 3 months. Of 1279 potential DDIs, Fourteen led to 13 ADRs out of which 8 were serious and caused hospital admission or prolongation of hospitalization. There was a statistically significant association between ADRs related to DDIs and the presence of ATC (Anatomical Therapeutic Chemical) C medication during hospitalization and the length of hospital stay, in the multivariate analysis.
  
  
  CONCLUSIONS
  Awareness of the most commonly occurring DDIs should be raised by the utilization of drug-drug interaction guides in the Romanian clinical practice which can help prescribers and pharmacists prevent DDI related ADRs.
authors.affiliation: University of Medicine and Pharmacy Iuliu Hatieganu, Drug Information Research Center, Cluj-Napoca, Pasteur Street No. 6, 400349, Romania. cfarah@umfcluj.ro
authors.forename: Camelia
authors.initials: C
authors.lastname: Bucşa
authors.forename: Andreea
authors.initials: A
authors.lastname: Farcaş
authors.forename: Irina
authors.initials: I
authors.lastname: Cazacu
authors.forename: Daniel
authors.initials: D
authors.lastname: Leucuta
authors.forename: Andrei
authors.initials: A
authors.lastname: Achimas-Cadariu
authors.forename: Cristina
authors.initials: C
authors.lastname: Mogosan
authors.forename: Marius
authors.initials: M
authors.lastname: Bojita
mesh_terms: D000368:Aged; D004347:Drug Interactions; D064420:Drug-Related Side Effects and Adverse Reactions / Q000209:etiology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies