title: Use of cisapride with contraindicated drugs in The Netherlands.
abstract: OBJECTIVE
  To investigate the prevalence of concomitant use and coprescribing of cisapride with potentially interacting drugs to evaluate the impact of these warnings from 1994 to 1998.
  
  
  METHODS
  Retrospective follow-up study of patients using cisapride.
  
  
  METHODS
  Data for this study were obtained from the pharmacy database of the Dutch PHARMO record linkage system (n = 834,000).
  
  
  RESULTS
  From 1994 to 1998, the prevalence rate of the observed versus expected use of any potentially interacting drug decreased significantly over time (p < 0.01). However, the number of days-at-risk and number of coprescriptions of potentially interacting drugs among cisapride users increased on average by 13% and 9% per year, respectively. This increase was almost exclusively explained by a large increase in concomitant prescribing of clarithromycin, the most commonly used potentially interacting drug. Decreases in prevalence rates were observed for all individual potentially interacting drugs, except for concomitant use of fluconazole and miconazole.
  
  
  CONCLUSIONS
  Over the last few years, healthcare professionals have refrained from dispensing potentially interacting drugs to patients who use cisapride, probably as a result of drug warnings implemented during this period. The limited absolute effects result from an increase of coprescription and concomitant use of clarithromycin and fluconazole among cisapride users. Because therapeutically equivalent alternatives were available for both drugs, such combinations were avoidable. Communicating information on these drug-drug interactions to prescribers and pharmacists and inclusion of cardiovascular morbidity as a relative contraindication for prescribing cisapride with these drugs may substantially decrease the risk of potentially adverse events to cisapride.
authors.affiliation: Institute for Pharmacoepidemiology and Outcomes Research, Utrecht, Netherlands. m.l.debruin@pharm.uu.nl
authors.forename: Marie L
authors.initials: ML
authors.lastname: De Bruin
authors.forename: Martien J M
authors.initials: MJ
authors.lastname: Panneman
authors.forename: Hubert G M
authors.initials: HG
authors.lastname: Leufkens
authors.forename: Arno W
authors.initials: AW
authors.lastname: Hoes
authors.forename: Ron M C
authors.initials: RM
authors.lastname: Herings
mesh_terms: D020117:Cisapride / Q000627:therapeutic use*; D017291:Clarithromycin / Q000627:therapeutic use; D000075202:Contraindications; D016208:Databases, Factual; D004347:Drug Interactions; D004348:Drug Labeling; D011307:Drug Prescriptions; D015725:Fluconazole / Q000627:therapeutic use; D005500:Follow-Up Studies; D006801:Humans; D008825:Miconazole / Q000627:therapeutic use; D009426:Netherlands; D012189:Retrospective Studies
chemical_list: D008825:Miconazole; D015725:Fluconazole; D017291:Clarithromycin; D020117:Cisapride