高齢患者の多剤併用療法における薬物相互作用の危険性

Abstract

As Japan becomes an increasingly aged society, we believe that a survey and analysis of prescription medication use by elderly patients will provide valuable information for selecting appropriate drug therapies. We surveyed changes in the number of outpatients examined and the number of concomitant drugs prescribed to elderly patients in our hospital, and the risk of adverse drug interactions in elderly patients undergoing polypharmacy.The ratio of elderly patients was relatively high in every department at our hospital except for pediatric patients. The total number of departments in which patients were examined tended to increase with age. The number of drugs taken in the elderly group was significantly larger than for the other groups, and the incidence of concomitant drug interaction increased with the number of drugs prescribed. As a result, a higher risk of adverse reactions to polypharmacy was observed in elderly patients.We therefore recommend devising a way to prescribe fewer drugs regarding both drug-interaction and the risk of adverse reaction. Elderly patients are examined in several departments and medical facilities, and so it is important to create a network system to centrally manage information on which drugs are actually prescribed, in order to avoid or decrease this risk.