Evaluation of clinical pharmacy services in patients receiving antithrombotic treatment in a randomized controlled trial

Patients receiving antithrombotic therapy are at increased risk of drug-related problems (DRPs) due to the complexity of their regimens and high-risk pharmacological profiles. Clinical pharmacists, through structured medication reviews and active collaboration with the healthcare team, have been shown to optimise pharmacotherapy, reduce medication errors, and improve patient safety outcomes. This study aimed to evaluate the impact of clinical pharmacy services on the identification and prevention of DRPs in hospitalised cardiology patients receiving antithrombotic drugs. A prospective, randomised controlled trial was conducted between November 2021 and November 2022 in the cardiology ward of a tertiary-care university hospital in Istanbul, Türkiye. Four hundred adult patients prescribed at least one antithrombotic agent (ATC group B01) were randomly assigned (1:1) to a control group, in which patients were monitored without intervention, or an intervention group, in which a clinical pharmacist performed a structured medication review using the Pharmaceutical Care Network Europe (PCNE) classification v9.1. Recommendations for resolving clinically significant DRPs were directly communicated to the physician in charge during multidisciplinary ward rounds. Patients were followed for unplanned readmissions at 1- and 3-months post-discharge. In the control group, the mean age was 67.2 ± 12.2 years, while in the intervention group it was 67.8 ± 12.3 years. Coronary artery disease and hypertension were the most prevalent comorbidities in both groups. A total of 561 DRPs were identified in the control group and 497 in the intervention group, with treatment safety and treatment effectiveness being the most common problem categories. Drug selection and dose selection were the leading causes of DRPs. In the intervention group, 248 recommendations for 266 clinically significant DRPs were made for 126 patients (63% of the group), of which 94.76% were accepted by physicians. The most frequent drug-level interventions were dose adjustments (29.65%) and initiation of new therapy (28.49%). The mean number of clinically significant DRPs per patient was significantly lower in the intervention group compared with the control group (p < 0.05). Active involvement of a clinical pharmacist within a multidisciplinary hospital team significantly reduced clinically significant DRPs in patients receiving antithrombotic therapy. These findings underscore the value of integrating clinical pharmacists into inpatient care to optimise pharmacotherapy and improve medication safety outcomes.