Concordance rate amongst electronic databases about drug interactions between warfarin and antimicrobials: a descriptive analysis.

Abstract

Drug interactions (DI) are adverse events that compromise therapeutic effectiveness and patient safety. Warfarin is associated with relevant DI with several drugs, including antimicrobials (AM). OBJECTIVE: to evaluate the degree of agreement between information on the probable mechanism, classification of severity and suggested management of potential DI between warfarin and AM present in the Municipal List of Medications of Porto Alegre (REMUME/POA), in the electronic databases (EDB) UpToDate®, Drugs.com®, Medscape® and Micromedex®. METHODOLOGY: descriptive analysis conducted in accordance with the Guidelines for Reporting Reliability and Agreement Studies. RESULTS: Of the twenty AM included, 17 had reported DI with warfarin in at least one of the four EDB. For the DI classification, the total concordance rate of the information obtained in the four consulted EDB was 30%; Partial agreement between two EDB was 25% and between three, 45%, and the EDB most in agreement with each other were UpToDate® and Drugs.com® (85%). As for the probable mechanism of the DI, the total agreement of the information was 12%; partial agreement between two EDB was 35% and between three, 23.5%, and the EDB that most agreed with each other were UpToDate® and Medscape® (47%). For the suggestion of clinical management, the total agreement was 18%; partial agreement between two EDB was 29%, and between three, 53%. The most concordant EDB were UpToDate® and Drugs.com® (82%). CONCLUSIONS: Total concordance rates between the EDB are relatively low; however, partial agreement is higher.