In this study, we investigated the efficacy of intervention by pharmacists who proactively recommended prescriptions to physicians as a countermeasure against polypharmacy. Based on the “Guidelines for medical treatment and its safety in the elderly 2015” and clinical findings at the time hospitalization, drugs that the patients were taking during admission were continued, discontinued, or replaced with other drugs. For many patients, the discontinued drugs constituted of laxatives, expectorants, hypolipidemics, intestinal regulators, hypouricemic agents, and electrolyte supplements, most of which were not in the guidelines. The proportion of patients for whom the number of medications was decreased by at least one was significantly higher in the intervention group than in the non-intervention group. Therefore, the benefits of decreased drug expense were more prominent in the former group than in the latter.

Objective: The aim of this study was to estimate medical economic costs associated with optimizing drugs brought to a cardiology hospital for inpatients with the help of pharmacists and doctors.

Methods: We optimized drugs brought to the hospital, compared patient backgrounds, and estimated medical economic costs.

Results: Medicine expenditure was 34.36 yen per day per patient post drug optimization with the help of pharmacists and doctors. Estimated glomerular filtration rates were significantly lower and patient ages and the number of prescriptions optimized were significantly higher in patients who regularly used 10 or more drugs than in those who used fewer than 10 drugs.

Conclusion: A drug cost reduction effect is expected with the collaboration between doctors and pharmacists, and with prescription optimization of drugs brought to a hospital.