High anticholinergic burden in patients referred from primary care to a tertiary memory care.

Background The anticholinergic burden (ACB) quantifies the cumulative anticholinergic drug exposure. Although a high ACB is associated with a greater risk of functional/cognitive decline, its usage is frequent in clinical practice. We aim to quantify the ACB and polypharmacy in referrals to a dementia tertiary outpatient clinic. Method A retrospective analysis was performed including medical records of referrals from primary care to the tertiary outpatient dementia clinic of the Hospital de Clínicas de Porto Alegre from 2014 to 2021. All medications were evaluated and ACB was measured with the Brazilian Anticholinergic Activity Drug (BAAD) score. It classified drugs according to its central anticholinergic activity from 1 to 3, with higher values indicating greater anticholinergic activity. BAAD score is the sum of anticholinergic activity of each drug, with scores above 3 meaning high ACB. Polypharmacy was defined as the use of > 3 drugs. A logist regression was performed using age, sex, dementia etiology, and Mini Mental State Examination (MMSE) as covariates. Result Among 398 referrals, 238 had a diagnosis of dementia: Alzheimer’s disease (AD) (34.4%), mixed type dementia (10.9%), vascular dementia (VD) (9.6%) and others (Frontotemporal, Lewy bodies, alcohol and others 26.9%). A total of 43 (18%) individuals had severe dementia, named unspecified dementia. Polypharmacy was frequent (277, 74.5%) and VD presented an increased number of medications when compared with other groups (7.2+‐3.1, p<0.002 for all). A third of patients with dementia were classified as high ACB (119, 32%), though dementia etiologies were not associated with BAAD (p = 0.13). In the regression analysis BAAD were associated with VD (OR 3.6, IC 95%: 1.34‐9.9) and other types of dementia (OR 2.4, IC 95%: 1.19‐5). BAAD had a significant correlation with Geriatric Depression Scale (GDS) (r = 0.23, p = 0.0002), but not MMSE (p = 0.07). Conclusion Most patients presented polypharmacy at arrival to a tertiary memory clinic, and a third presented a high ACB. VD was a predictor of ACB score, and they may be at a greater risk of cognitive and functional worsening.