Association of anticholinergic burden with Parkinson's disease severity and stage

Objectives: The study aimed to investigate the association of anticholinergic burden with polypharmacy, the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), and the modified Hoehn and Yahr (HY) staging system in Parkinson's disease (PD). Patients and methods: The cross-sectional study included 75 patients (38 males, 37 females; mean age: 65.7±9.6 years; range, 32 to 86 years) who were admitted between January 2023 and January 2024. Demographic characteristics, systemic diseases, medications, MDS-UPDRS, and modified HY were recorded. Polypharmacy was defined as the use of five or more medications at the same time. The anticholinergic burden was calculated using the Anticholinergic Cognitive Burden (ACB) scale. Patients were divided into two groups: those with an ACB risk score ≥3 (high risk) and those with a risk score <3 (low risk). Results: When analyzed according to ACB scale risk status, 41 patients with PD were found to be at high risk for anticholinergic burden (score ≥3). The presence of at least one comorbid disease was more common in the high-risk group than in the low-risk group (p<0.05). The presence of unipolar depression was higher in the high-risk group (p=0.001). Frequency of polypharmacy was higher in the high-risk group (73.2% vs. 32.4%; p=0.001). In regression analysis, a high ACB score was statistically associated with modified HY Stage 4 when confounding factors were excluded (odds ratio=12.80; p=0.030). Conclusion: Patients with polypharmacy in PD had higher ACB scores (>3) and depression as a comorbidity in these patients. A high ACB risk score was associated with modified HY Stage 4 when adjusted for confounding factors. The anticholinergic risk might be highest in the advanced stage of PD. Therefore, patients diagnosed with PD should be questioned about their drug history and evaluated for anticholinergic drug use at every visit.