Anticholinergic burden in Parkinson's disease inpatients.

PURPOSE: Anticholinergic toxicity can arise as a result of the cumulative burden of multiple medications and metabolites rather than be caused by a single compound. In this sense, prescribing drugs with anticholinergic properties to Parkinson's disease (PD) patients could contribute to aggravate some frequent problems of the disease, like dementia, urinary retention, falls, or constipation, among others. The main purpose of this article is to measure the total anticholinergic burden in a group of PD inpatients.

METHOD: We analyzed information from different administrative Basque Country's healthcare databases using encrypted unique identifiers in order to detect PD patients admitted to public acute care hospital during 2011-2012. Subsequently, anticholinergic burden was measured using Duran et al.'s list. Secondarily, total anticholinergic load was assessed with the Anticholinergic Drug Scale, the Anticholinergic Risk Score, and the Anticholinergic Burden Scale. A logistic regression model was performed to study association of predictive variables with anticholinergic use.

RESULTS: A high proportion of PD patients were prescribed anticholinergic drugs, with 53.6% of admissions receiving at least one drug from Duran et al.'s "low-risk" and 10% at least "high-risk" drug. Drugs used for non-motor symptoms and other comorbidities other than PD itself contributed significantly to anticholinergic burden, namely antidepressants, antipsychotics, urological drugs, analgesics, and antihistamines, among others. The total number of drugs and cholinesterase inhibitors were independently associated with anticholinergic drug use.

CONCLUSIONS: Anticholinergic burden in PD patients is significant, and is caused mostly by drugs not used for PD motor symptoms. Polypharmacy and cholinesterase inhibitors were independently associated with anticholinergic drug prescriptions.