The present study investigated the status of potentially harmful drug–drug interactions (PHDI) in older adults, to obtain insight into factors that influence the risk of PHDI.Methods
The present study included Korean people aged ≥65 years who were prescribed one or more drugs included in the list of PHDI under the Beers Criteria 2015 from January to December, 2016 (n = 1 257 317). PHDI were defined based on the Beers Criteria 2015. Among 10 PHDI, a prevalence of >5% was taken to be clinically significant, and the relationships between multiple variables and PHDI were examined.Results
The most frequent PHDI was corticosteroids and non-steroidal anti-inflammatory drugs (n = 259 499, 20.64%), followed by a combination of two or more anticholinergic drugs (n = 139 622, 11.1%), and three or more drugs acting on the central nervous system (n = 86 023, 6.84%). These three types of PHDI were more frequent in women (OR 1.066–1.141) and medical aid beneficiaries (OR 1.095–1.510). The risk of PHDI increased in proportion to the number of healthcare institutions used by the participants and their outpatient visits during the year (OR 1.043–1.079, 1.008–1.010, respectively). The risk of PHDI was low when patients took no more than five medications in a single prescription (OR 0.017–0.791).Conclusions
The findings of the present study highlight the three most frequent PHDI in Korea according to the Beers Criteria 2015. Healthcare providers should take PHDI into account when treating female patients, medical aid beneficiaries, patients using multiple healthcare institutions, frequent outpatient visitors and patients prescribed more than six medications in a single prescription. Geriatr Gerontol Int 2018; ••: ••–••.