Drug-related problems in head and neck cancer patients identified by repeated medication reviews on consecutive therapy cycles

Background: Head and neck cancer (HNC) patients are particularly vulnerable to drug-related problems (DRPs) given the toxicity of concomitant chemoradiotherapy (CCRT).

Objective: To investigate the number and type of potential DRPs (pDRPs) in HNC outpatients undergoing five consecutive cycles of CCRT.

Methods: A single-centre, non-randomized, non-interventional, observational study was conducted at the Oncological Outpatient Clinic of the Center for Integrated Oncology at the University Hospital Bonn, Germany. Clinical pharmacists took a comprehensive medication history, documented laboratory data, assessed patients' symptom burden, and retrospectively performed medication reviews at study entry and on the first day of each therapy cycle without any clinical intervention.

Results: In 26 patients, the mean number of pDRPs continuously increased during therapy course, from 4.8 (SD 2.7, range 2-12) at cycle 1 to 6.9 (SD 2.6, range 2-12) at cycle 5, with drug-drug interactions, adverse drug reactions, inappropriate durations of use, and inappropriate dosage intervals being the most common. Considering only new and recurrent pDRPs, the mean number was 4.3 (SD 2.3, range 2-9) at cycle 1 and lower in the further therapy course with an average of 1.3 (SD 1.7, range 0-7) at cycle 2 and 1.9 (SD 1.5, range 0-5) at cycle 5. The number of pDRPs was found to be associated with medication regimen complexity and health-related quality of life assessed in the first therapy cycle.

Conclusion: pDRPs frequently occurred in HNC outpatients demonstrating the need for pharmaceutical care. A methodological framework for repeated medication reviews was established, facilitating implementation into routine healthcare practice.