title: [Potential drug interactions and number of prescription drugs with special instructions at hospital discharge].
abstract: OBJECTIVE
  Up to 6% of all hospitalizations are due to adverse drug reactions and 20% of these are caused by drug-drug interactions. There is only little information on the prescription frequency of drug-combinations with the potential to induce dangerous drug-drug interactions and drugs with the need for special patient instruction (e.g. inhalers). The aim of our study was to investigate the frequency of such drug prescriptions at hospital discharge.
  
  
  METHODS
  In a retrospective, descriptive study drug prescriptions of 100 patients discharged consecutively from the department of internal medicine of a 300 bed-hospital were analysed. Possible drug-drug interactions were detected using a special computer program. Furthermore, the number of prescriptions warranting patient instruction such as anticoagulants, antidiabetics, hormones, immunosuppressive drugs, chemotherapeutics, antituberculotic and antiepileptic drugs as well as inhalatives and injections was recorded.
  
  
  RESULTS
  The mean age of the 100 patients (61 men, 39 women) was 61.7 years, the mean duration of the hospital stay was 9.2 days. At discharge, patients took an average of 3.5 different drugs. Half of the patients were given drug-combinations with the potential for drug-drug interactions, whereby 5% were at risk for the development of interactions of severe and 42% of intermediate degree. All drug-combinations with potentially severe interactions were prescribed deliberately. 31% of all patients took medications with the need for special education, with inhalatives being the most frequent. The prescription of drugs with potential interactions and the necessity for special patient instruction was more frequent in the elderly.
  
  
  CONCLUSIONS
  Drug-combinations with the potential of harmful interactions and drugs with the requirement for special patient instruction are frequently prescribed at hospital discharge. The frequency of prescribing these drugs increases with age. Detection of potentially dangerous drug-drug interactions is simplified by special computer programs. Careful patient instruction about the use of certain drugs is a key issue to improve patient compliance and to guarantee an optimal treatment effect.
authors.affiliation: Medizinische Klinik, Rätisches Kantons- und Regionalspital, Chur.
authors.forename: P O
authors.initials: PO
authors.lastname: Bonetti
authors.forename: K
authors.initials: K
authors.lastname: Hartmann
authors.forename: M
authors.initials: M
authors.lastname: Kuhn
authors.forename: W H
authors.initials: WH
authors.lastname: Reinhart
authors.forename: T
authors.initials: T
authors.lastname: Wieland
mesh_terms: D000368:Aged; D004347:Drug Interactions; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004359:Drug Therapy, Combination; D004363:Drug Utilization; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010351:Patient Discharge / Q000706:statistics & numerical data*; D012307:Risk Factors; D013557:Switzerland