A prescription survey about combined use of acetylcholinesterase inhibitors and anticholinergic medicines in the dementia outpatient using electronic medication history data from community pharmacies

PURPOSE: We investigated prescriptions regarding the combined use of donepezil hydrochloride (DPZ) and anticholinergics for elderly outpatients in Japan to determine the impact that combination therapy has on decreasing their cognitive functions. METHODS: Using electronic medication records from 142 community pharmacies, outpatients older than 40 years of age taking DPZ, with or without other prescription medicines, were assessed over 6 years, beginning in 2007. We estimated the number of medicines administered along with DPZ, the number of anticholinergics administered along with DPZ, and the medicines’ anticholinergic cognitive burden (ACB) scale cumulative score based on data from the top four pharmacies that filled the highest number of prescriptions for DPZ for outpatients with dementia in 2010. Data were gathered from records of 431 patients; only three patients were younger than 60 years. RESULTS: There was a 1.94-fold increase in the number of prescriptions including DPZ over 6 years. The proportion of patients to whom other medicines were administered along with DPZ was 65.6% (n=283) and the proportion of those taking at least one anticholinergic agent was 24.1% (n=104). The mean number of medicines among subjects taking at least one anticholinergic was 5.7, and the mean cumulative ACB score for anticholinergics contained in these medicines was 2.6. Among 104 patients to whom the anticholinergics were administered along with DPZ, two outpatients taking urologic medicines such as oxybutynin hydrochloride or tolterodine tartrate were found. CONCLUSION: Our findings suggest that it is necessary to pay attention to a decline in cognitive function when prescribing multiple medicines, especially to elderly patients who have already been prescribed DPZ.