Role of a Designated Pharmacist in Reducing Adverse Drug Reaction Rates and Preventing Potential Medication Errors in Hematology-Oncology: A Randomized Controlled Trial.

Purpose: Evidence is insufficient regarding pharmacists' impact on reducing adverse drug reactions (ADRs) in oncology. This trial evaluated whether including a designated pharmacist in the hematology-oncology team reduced ADRs compared with standard care.

Methods: This single-center randomized clinical trial was conducted at its outpatient hematology-oncology clinics from July 2020 to October 2022. All consecutive patients meeting study criteria were randomly assigned to receive comprehensive pharmacist intervention or standard care in a 1:1 ratio. Outcomes were monitored over the 4-month intervention period and 1 month afterward. In the intervention group, the pharmacist evaluated treatments, provided medication counseling, and made recommendations to physicians. The control group's treatment charts were evaluated after the intervention ended. In both groups, unrelated pharmacologist physicians determined which recommendations were medication errors (MEs) and assessed their severity levels. The primary outcome was the rates of ADRs. The analysis used the intention-to-treat principle.

Results: The study included 182 patients, 91 in each group. The intervention group had lower ADR rates, with an age-adjusted hazard ratio (aHR) of 0.38 (95% CI, 0.23 to 0.65; P < .001) for at least one ADR and an aHR of 0.25 (95% CI, 0.09 to 0.67; P = .006) for at least one moderate or severe ADR. The pharmacist made 588 recommendations for the intervention group, 95% of which were implemented, and identified 287 as MEs. The intervention group also had a higher incidence of detected administration errors (incidence rate ratio, 2.61; 95% CI, 1.38 to 4.92; P = .003) and a higher proportion of potentially serious MEs (P = .003).

Conclusion: Integrating an oncology pharmacist into hematology-oncology clinics reduces ADRs and improves the detection and prevention of potentially serious MEs.