Drug interactions in female oncologic inpatients: differences among databases

The aim of the present study was to quantify drug interactions in prescriptions for women undergoing supportive therapy in an oncology setting at a women’s hospital in Brazil and compare the information provided by different databases regarding these drug interactions. A convenience sample was selected of prescriptions for patients diagnosed with breast or gynecological tumors hospitalized in the clinical oncology and surgery wards from April to June 2009. DRUGDEX/Micromedex (Thomson Micromedex) was the main database used for the identification of drug interactions and was compared with two other databases: Drugs.com and Lexicomp. The search was performed by inputting all drug combinations found in the prescriptions in Micromedex and Drugs.com. All interactions identified and classified by Micromedex and/or Drugs.com as of major severity were then checked in Lexicomp. A total of 152 interactions were identified by Micromedex (61 major, 69 moderate and 22 minor). In Drugs.com, 614 interactions were identified (85 major, 464 moderate and 65 minor). Forty-four were classified as major drug interactions in at least one of the databases: 30 in Micromedex, 26 in Drugs. com and 14 in Lexicomp. The present findings reveal discrepancies among the three databases analyzed. Thus, standardization should be proposed. Moreover, both the pharmacist and multidisciplinary team should perform a critical analysis of prescriptions to promote safe practices in the use of medications and minimize potential complications caused by drug interactions.