Controversies in anticholegenic medication use and cognitive impairment

As many as 40% of older people are prescribed medications with anticholinergic activity. Studies have suggested the significant effect of anticholinergic medication on cognition but there is controversy. Objective: Analysis of 15908 patients impact of anticholinergic drugs on cognition. Methods: The anticholinergic burden scale (ABS) coded drugs 0 (none), 1 (mild), 2 (moderate), or 3 (severe). Scores were summed for each participant to give a total Anticholinergic Cognitive Burden (ACB) score. Study 1 MRC CFAS with 11,994 participants and cross sectional coding part of a 19 year longitudinal; Study 2 LASER-AD - Dementia Specific 18 month longitudinal with 224 participants. Study 3 SAP REDS USA 1 year follow up with 3690 participants. Study 1 MRC-CFAS - A statistically significant dose-response relation was observed between increasing ACB score and decreasing MMSE, e.g. those with an ACB score of 5 or greater were associated with making 21% (95%CI 8%-35%) more errors on the MMSE. The relationship with cognitive impairment was only seen for ACB conferred by Central Nervous System medications, in particular antipsychotics. Study 2 LASER AD - Anti-cholinergic burden had no significant effect on cognitive decline at 18 months as assessed by the ADAS-cog. The ADAS-cog decreased by a mean of 4.63 in the cohort of patients with an ACB of 0, compared with a mean decrease of 7.4 in patients with an ACB of>0 (mean difference=2.83; t=1.107; df=100; p=0.271; CI-2.24-7.9). Study 3 SAP REDS - Anticholinergic burden for 60 days was associated with a significant effect on cognitive decline as measured by the Community Screening Interview for Dementia odds ratio 1.55p<0.05 (CI-1.05-2.29) with a possible burden dose response effect. Conclusion: An inverse relation existed between the anticholinergic burden of current medication use and cognition in study 1 and study 3; in study 1 the association was driven by the ACB of CNS medications. However, in study 2 no association was detected. Thus the abandonment of use of medication with anticholinergic effects may not be warranted. Further research is required to determine the clinical relevance.