title: Incidence of Potential Drug-Drug Interactions in a Limited and Stereotyped Prescription Setting - Comparison of Two Free Online Pharmacopoeias.
abstract: BACKGROUND
  Drug-drug interactions (DDIs) are very common adverse events in health care delivery settings. The use of electronic pharmacopeias can potentially reduce the incidence of DDIs, but they are often thought to be cumbersome to use. This study is aimed at studying the incidence of potential DDIs in a surgical department, where a limited number of drugs are used in stereotyped combinations. We also compared two popular drug compendia in detecting potential DDIs.
  
  
  METHODS
  The prescriptions of selected patients were entered into Epocrates® and Medscape® for Android smartphones. Potential DDIs were generated and their categories were noted. The warnings generated by Epocrates® were compared with those generated by Medscape® and an agreement index was calculated.
  
  
  RESULTS
  Three hundred and thirty-one patients were included for analysis who had received a total of 2,878 drug orders. The incidence of potential DDIs was very high - 89% of all prescriptions. Phenytoin was the drug most commonly implicated, followed by furosemide. Of the DDIs detected, 0.14% were potentially serious and the drug combinations were contraindicated. There was a significant discrepancy between the categories of potential DDIs detected by Epocrates® and Medscape®. No clinically significant DDI was detected in any patient in this cohort.
  
  
  CONCLUSIONS
  Despite routinely using only a limited number of drugs in stereotyped combinations, prescriptions in surgical departments may not be immune from a significant incidence of DDIs. The use of free apps could reduce the incidence of DDIs, enhance patient safety, and also aid in educating trainees.
authors.affiliation: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
authors.forename: Bhaskar
authors.initials: B
authors.lastname: Kannan
authors.affiliation: Department of Anesthesiology and Critical Care, Mahatma Gandhi Medical College and Research Institute, Pondicherry, India.
authors.forename: Amrutha Bindu
authors.initials: AB
authors.lastname: Nagella
authors.affiliation: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
authors.forename: A
authors.initials: A
authors.lastname: Sathia Prabhu
authors.affiliation: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
authors.forename: Gopalakrishnan M
authors.initials: GM
authors.lastname: Sasidharan
authors.affiliation: Department of Neurosurgery, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, India.
authors.forename: A S
authors.initials: AS
authors.lastname: Ramesh
authors.affiliation: Division of Neurosurgery, Tata Memorial Hospital, Mumbai, India.
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Madhugiri
keywords: adverse drug reactions; drug interactions; epocrates; medscape; patient safety