RESUMEN
PURPOSE: Older people are especially vulnerable to negative anticholinergic effects. Although anticholinergic drugs are commonly used among older people, drugs with potent antimuscarinic properties are considered as potentially inappropriate medications for older people. Here, we examined features of anticholinergic use and investigated predictors for the high use of strong anticholinergic agents (ACs) in the elderly. METHODS: A total of 388,629 Korean elderly aged ≥70 years were recruited from the 2012 National Health Insurance Service Elderly cohort database. The use of ACs in 2012 was quantitatively assessed by calculating standardized prescribed doses. Multivariate logistic regression was conducted to identify predictors of the high use of strong ACs (≥90 doses). RESULTS: Almost half of the subjects (47.2%) used more than 15 doses of strong ACs during 2012. 17.0% of the subjects had an annual cumulative use of strong ACs over 90 doses. Morbidities such as depression (odds ratio [OR], 95% confidence interval [CI] = 2.56, 2.48-2.63), Parkinson's disease (2.41, 2.26-2.56), genitourinary diseases (2.12, 2.07-2.16), polypharmacy (3.28, 3.21-3.36), and low income (1.29, 1.25-1.33) were strong predictors of their high use. Antihistamines (chlorpheniramine) and antidepressants (amitriptyline) greatly contributed to the total prescription of strong ACs. CONCLUSIONS: Despite the vulnerability of older people to the adverse reactions of strong ACs, their use seems to be at a high level in terms of cumulative usage among some elderly. More attention should be paid to older people with predictive factors of high use of strong ACs. Key points Despite the susceptibility of older people to negative anticholinergic effects, high use of strong anticholinergic agents was is quite frequent; 17.0% of the elderly had an annual cumulative use of these drugs ≥90 doses. Parkinson's disease, depression, genitourinary diseases, low income, and polypharmacy strongly predicted the high use of strong anticholinergic agents. A few strong anticholinergic agents, including antihistamines (chlorpheniramine) and antidepressants (amitriptyline), accounted for the majority of medications prescribed. Understanding the predictors of their high use by medical practitioners may result as more appropriate anticholinergic medications.