BackgroundHospital admission and discharge are at high risk of drug‐related problems (DRPs) in older patients with cancer. This study aimed to assess the clinical and economic impact of a comprehensive pharmaceutical care intervention (RECAP) to optimize drug therapy in patients with cancer ≥75 years admitted to oncology or geriatric wards.MethodRECAP intervention was defined as follows: at admission and discharge, hospital pharmacists conducted comprehensive medication reconciliation and review, identified relevant DRPs and provided optimization recommendations to prescribers; at discharge, pharmacists also provided patient education and shared information with primary care providers. The impact of the intervention was assessed by the rate of implementation of recommendations by the prescribers and the evolution of polypharmacy rate; a peer review of the clinical significance of DRPs was performed by an expert panel of geriatric oncologists and pharmacists. A cost saving analysis compared cost avoided through resolution of DRPs to cost of pharmacist's time.ResultsFrom January 2019 and August 2020, 201 patients were included (median age 80 [75–97] years), 68.7% with solid tumors. DRPs requiring optimization were identified in 70.9% of patients at admission (mean 1.7 DRP/patient) and 47.7% at discharge (0.9 DRP/patient). Most pharmacist recommendations (70.8%) were followed by prescribers, allowing the correction of 1.2 DRP/patient at admission and 0.7 DRP/patient at discharge. Half of resolved DRPs were rated as clinically significant. However, polypharmacy rate was not reduced at discharge. Cost comparison showed $7.2 avoided for $1 invested, with an estimated total net benefit of $354,822 (mean $1766 per patient).ConclusionsThe RECAP model significantly reduces DRPs in hospitalized older patients with cancer. The model was cost saving, confirming the value of implementing it in routine practice.