title: Prevalence of potential drug-drug interactions in bone marrow transplant patients.
abstract: OBJECTIVE
  To assess the prevalence of potential drug-drug interactions (DDIs) in bone marrow transplantation (BMT) patients at the time of pre-infusion (day -1), to describe the potential DDIs and assess their frequency and severity.
  
  
  METHODS
  The study was developed in a tertiary care hospital in São Paulo, Brazil.
  
  
  METHODS
  Cross-sectional study based on examining the medical prescriptions from the pre-infusion day (day -1) of 70 BMT patients. Potential DDIs were analyzed using Drug-Reax(®) and categorized according to levels of severity, evidence, and onset (rapid and delayed). Only interactions of major or moderate severity were included in the potential DDI analysis.
  
  
  METHODS
  Prevalence of potential DDIs in patients during the preinfusion phase of BMT.
  
  
  RESULTS
  Data were analysed for 70 BMT patients. The median age was 36.5 years; 52.9% (37) of the patients were male, and 65.7% (46) were undergoing autologous BMT. The patients received a median of 8 drugs each. Up to 128 potential DDIs were detected, 60.0% (42) of patients had at least 1 potential DDI and 21.4% (15) were exposed to at least 1 major potential DDI. The most commonly involved drugs were cyclosporine (9, 28.1%), phenytoin (8, 25%) and fluconazole (5, 15.6%). Most potential DDIs had moderate severity (110, 85.9%), a pharmacokinetic mechanism (67, 52.3%), and were classified as delayed onset (106, 82.8%). For major interactions, fluconazole + sulfamethoxazole/trimethoprim, diazepam + fentanyl, fluconazole + levofloxacin and fentanyl + fluconazole were the most frequent.
  
  
  CONCLUSIONS
  The prevalence of potential DDIs during the conditioning period of BMT was high as a consequence of the therapeutic complexity of the procedure. Most potential DDIs identified in the study may result in clinically relevant consequences as they could lead to nephrotoxicity, cardiotoxicity, and other undesirable adverse effects. Careful monitoring of clinical and laboratory parameters is essential to ensure a successful BMT and to avoid adverse drug events related to DDI.
authors: Instituto do Coração, Hospital das Clínicas, University of São Paulo, São Paulo, Brazil.
authors: Rosimeire Barbosa Fonseca
authors: RB
authors: Guastaldi
authors: Adriano Max Moreira
authors: AM
authors: Reis
authors: Albert
authors: A
authors: Figueras
authors: Silvia Regina
authors: SR
authors: Secoli
mesh_terms: D000328:Adult; D000368:Aged; D016026:Bone Marrow Transplantation / Q000379:methods*; D001938:Brazil; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D016903:Drug Monitoring; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism; D015995:Prevalence; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult
chemical_list: D004364:Pharmaceutical Preparations