Evaluation of oral targeted anticancer drug interactions and their management by oncology pharmacists

Abstract

Introduction

Oral targeted anticancer drugs (OTADs) have become a key component of therapy for multiple malignancies, and their use continues to expand. While several studies have identified numerous drug interactions (DIs) associated with these oral therapies, very few have described the role of an oncology pharmacist in DI management.

Objectives

The purpose of this study was to quantify moderate/severe DIs with OTADs at initiation and describe the role of the pharmacist in interaction detection and management.

Methods

This retrospective analysis was completed utilizing an electronic health record review of adult patients initiated on an OTAD with pharmacist documentation of medication review between July 2020 and July 2022. The outcomes of this study included the incidence of moderate/severe DIs, the distribution of pharmacokinetic/pharmacodynamic DIs, the incidence of pharmacist documentation of moderate/severe DIs, prescriber acceptance of documented pharmacist-recommended interventions, the evaluation of severe DIs, and presence of DI related adverse effects within 60 days of OTAD initiation.

Results

Two hundred sixty-six patients were included. Forty-six percent (122/266) of patients had at least one moderate/severe DI identified by investigators with a total of 220 moderate/severe DIs detected. Fifty-eight percent (127/220) of the identified DIs were pharmacokinetic and 42% (93/220) were pharmacodynamic in nature. Pharmacist documentation was present for 36% (75/207) of the moderate DIs and 92% (12/13) of the severe DIs identified at OTAD initiation, and prescribers accepted 94% (82/87) of the pharmacists' recommended interventions. Lastly, 12.5% (26/208) of the incidence of adverse effects was potentially related to moderate/severe DIs within 60 days of OTAD initiation.

Conclusion

Clinically significant (moderate/severe) DIs are common in patients receiving OTADs and may impact patient outcomes. Pharmacists can help to identify, prevent, and create a plan of action for the management of DIs and we advocate for their involvement in the management of OTAD therapies.