Use of Tricyclic Antidepressants and Other Anticholinergic Medicines by Older Aboriginal Australians: Association with Negative Health Outcomes

Background: Aboriginal and Torres Strait Islander Australians have a relatively high prevalence of multimorbidity requiring treatment with medications. This study examines medication use and anticholinergic burden (ACB) among a cohort of older Aboriginal and Torres Strait Island people. Method: This cross-sectional study involving five Aboriginal communities (two in metropolitan Sydney and three on the mid-north coast of New South Wales) used a structured interview process to assess cognition, depression, and activities of daily living for a cohort of older adults (aged 60 years and over). Participants also reported on their health status, medical history, and prescription medications during the interview. ACB was calculated, and its association with adverse health outcomes including cognitive impairment, falls, hospitalization, and depressive symptoms were examined. Results: Most participants (95%) were taking at least one regular medication with polypharmacy (>= 5 medications) observed in 43% of participants; 12.2% had a significant ACB (>= 3) with antidepressants being a major contributor. Anticholinergic medication use was associated with cognitive impairment, recent hospitalization (past 12 months), and depressive symptoms. After controlling for age, sex, and comorbidity, only the presence of depressive symptoms remained significantly associated with the use of anticholinergic medication (odds ratio 2.86; 95% confidence interval 1.48-5.51). Conclusions: Clinically significant ACB was common in older Aboriginal Australians and was largely attributable to inappropriate use of tricyclic antidepressants. Greater awareness of medication-related risk factors among both health care professionals and Aboriginal communities can play an important role in improving health and quality of life outcomes.