Prescription patterns of anticholinergic agents and their associated factors in Korean elderly patients with dementia

Background Dementia is a disorder that is characterized by a chronic, progressive loss of cognitive function. Anticholinergic agents that are often used with elderly patients may cause a decline in cognitive capacity; therefore, they must be used with caution. Objective We aimed to identify the prescription patterns for anticholinergic drugs in elderly outpatients with a documented diagnosis of dementia through a retrospective analysis of electronic medical records. In addition, the study aimed to identify factors influencing these prescription patterns. Setting The Kyung Hee University Hospital in Korea. Methods We studied outpatients aged ≥65 years registered with dementia between January 1, 2011 and December 31, 2011. We reviewed prescription histories, identified anticholinergic prescriptions during the study period using the anticholinergic risk scale (ARS), and examined prescription patterns in the subjects. After analysing the ARS scores for each drug and subject, we performed a statistical analysis of the factors affecting prescription patterns for anticholinergic medications in patients with ARS scores of ≥2. Main outcome measure Prescription data on anticholinergic agents. Results Of 773 elderly dementia patients, 362 patients (46.83 %) were prescribed at least one anticholinergic medication. Of the ARS 2-point anticholinergics, nortriptyline was prescribed most frequently. Among ARS 3-point anticholinergics, cyproheptadine was prescribed most frequently. An ARS score of ≥2 was given in 255 (32.98 %) patients. A multivariate logistic regression analysis of the factors associated with anticholinergic prescription patterns revealed that those patients with comorbid Parkinson’s disease received significantly fewer prescriptions (OR = 0.544; 95% CI 0.364–0.813) and those patients who were prescribed 6–10 or ≥11 medications were significantly more likely to receive anticholinergic prescriptions (OR = 3.410; 95 % CI 2.228–5.220 and OR = 4.688; 95 % CI 2.993–7.344, respectively). Conclusion Approximately 33% of the elderly dementia patients in this study were prescribed clinically significant medication regimens totaling an ARS score of ≥2. Our findings show that the total number of medications and comorbid Parkinson’s disease both influence prescription patterns for anticholinergic medications.