title: Potential drug interactions in cancer therapy: a prevalence study using an advanced screening method.
abstract: BACKGROUND
  In cancer patients, drug interactions may intensify adverse events or reduce antitumour effects. We assessed the prevalence of potential drug interactions (PDIs) among ambulatory cancer patients on i.v. treatment using an advanced screening method.
  
  
  METHODS
  Data on drugs used for comorbidities, anticancer agents, over-the-counter (OTC) drugs, and comorbidities were collected by means of a structured interview among the patients and review of medical charts. PDIs were identified using electronic (Drug Interaction Facts software, version 4.0) and manual screening methods (peer-reviewed reports).
  
  
  RESULTS
  In this study, 278 patients were enrolled. We identified 348 PDIs. Of all patients, 161 (58%) had at least one PDI. Of all PDIs, 34% was classified as major and 60% as moderate. Coumarins, quinolones, antiepileptics, and hydrochlorothiazide were frequently part of a PDI. Interactions that potentially cause QT interval prolongation, gastrointestinal toxicity, and central nervous system depression were also common. In multivariate analysis, an increasing number of drugs [odds ratio (OR) = 1.4, confidence interval (CI) 1.23-1.52; P < 0.001] and the use of an OTC drug (OR = 0.56, CI 0.32-0.97; P = 0.045) were risk factors.
  
  
  CONCLUSIONS
  PDIs are common in patients treated for an (haemato-) oncological disease. Screening for potential interactions should take place routinely before administering chemotherapy.
authors.affiliation: Department of Clinical Pharmacology and Pharmacy, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: R W F
authors.initials: RW
authors.lastname: van Leeuwen
authors.forename: E L
authors.initials: EL
authors.lastname: Swart
authors.forename: E
authors.initials: E
authors.lastname: Boven
authors.forename: F A
authors.initials: FA
authors.lastname: Boom
authors.forename: M G
authors.initials: MG
authors.lastname: Schuitenmaker
authors.forename: J G
authors.initials: JG
authors.lastname: Hugtenburg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000494:pharmacology; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D004366:Nonprescription Drugs / Q000008:administration & dosage* / Q000494:pharmacology; D012307:Risk Factors; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents; D004366:Nonprescription Drugs