Drug interactions with oral antineoplastic drugs: The role of the pharmacist

Abstract

The main objective of the study is to determine the pharmacist detection of drug-drug and drug-food interactions in patients receiving oral antineoplastic drugs (OADs). Descriptive, prospective study in a tertiary-care teaching hospital. The study population included patients who received OADs from the Outpatient Pharmacy of the hospital. The study population was attended by a pharmacist who checked potential interactions. The severity of interactions was evaluated using the summary of product characteristics of each drug and three different databases. We included 219 patients with a total of 736 concomitant medications. A total of 34 drug-drug or food-drug interactions were recorded. The most common interaction detected was between erlotinib and ranitidine (major interaction). In 19 of the 34 interactions detected in the experimental group, the pharmacist prevented them from reaching the patient. Interactions were resolved by drug suspensions, drug changes, or changes in schedules always according to the attending physician or the patient. In the remaining 15 interactions, the doctor was not contacted because the interactions were considered to be of little relevance or because they only required surveillance. Hospital pharmacist can improve the patient's safety and the efficiency of oral cytostatic treatment by detecting and preventing drug-drug and drug-food interactions.

Keywords: drug interactions; grapefruit; oral antineoplastic drug; pharmacist intervention.