title: Adverse drug reactions and drug interactions as causes of hospital admission in oncology.
abstract: BACKGROUND
  Although several studies have evaluated the frequency of adverse drug reactions (ADRs) and drug-drug interactions (DDIs) in general medicine, few studies have looked at the epidemiology of adverse drug events (ADEs) in oncology.
  
  
  OBJECTIVE
  We sought to investigate how many hospital admissions in oncology are related to a DDI or an ADR.
  
  
  METHODS
  All cancer patients admitted to an oncology ward during an eight-month period had their charts retrospectively evaluated for reasons of hospitalization, using a 4-point scale (definitely, probably, possibly, or unlikely associated) to classify admissions by their probability of being associated with either a DDI or an ADR.
  
  
  RESULTS
  From September 2007 to May 2008, there were 550 hospital admissions and 458 were eligible. Among unplanned admissions (n=298), 39 (13.0%, 95% confidence interval [CI] 9.4%-17.4%) were considered to be associated with an ADE, 33 (11.0%, 95% CI 7.7%-15.2%) with an ADR, and six (2.0%, 95% CI 0.7%-4.3%) with a DDI. The most common DDIs involved warfarin, captopril, and anti-inflammatory agents, and the most frequent ADR was neutropenic fever post-chemotherapy. Most patients were discharged completely recovered, but two patients died.
  
  
  CONCLUSIONS
  Approximately one in 10 unplanned hospitalizations of cancer patients is associated with an ADE. Prospective and population-based studies are warranted to evaluate their magnitude in oncology.
authors: ABC School of Medicine, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors: Vanessa
authors: V
authors: Miranda
authors: Angelo
authors: A
authors: Fede
authors: Melissa
authors: M
authors: Nobuo
authors: Veronica
authors: V
authors: Ayres
authors: Auro
authors: A
authors: Giglio
authors: Michele
authors: M
authors: Miranda
authors: Rachel P
authors: RP
authors: Riechelmann
mesh_terms: D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D004347:Drug Interactions; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016522:Oncology Service, Hospital / Q000706:statistics & numerical data*; D010343:Patient Admission / Q000706:statistics & numerical data*; D012189:Retrospective Studies