Use of drugs with anticholinergic effect and impact on cognition in Parkinson's disease: a cohort study.
BACKGROUND
Cognitive decline is common in Parkinson's disease (PD). Although some of the aetiological factors are known, it is not yet known whether drugs with anticholinergic activity (AA) contribute to this cognitive decline. Such knowledge would provide opportunities to prevent acceleration of cognitive decline in PD.


OBJECTIVE
To study whether the use of agents with anticholinergic properties is an independent risk factor for cognitive decline in patients with PD.


METHODS
A community-based cohort of patients with PD (n=235) were included and assessed at baseline. They were reassessed 4 and 8 years later. Cognition was assessed using the Mini-Mental State Examination (MMSE). A detailed assessment of the AA of all drugs prescribed was made, and AA was classified according to a standardised scale. Relationships between cognitive decline and AA load and duration of treatment were assessed using bivariate and multivariate statistical analyses.


RESULTS
More than 40% used drugs with AA at baseline. During the 8-year follow-up, the cognitive decline was higher in those who had been taking AA drugs (median decline on MMSE 6.5 points) compared with those who had not taken such drugs (median decline 1 point; p=0.025). In linear regression analyses adjusting for age, baseline cognition and depression, significant associations with decline on MMSE were found for total AA load (standardised beta=0.229, p=0.04) as well as the duration of using AA drugs (standardised beta 0.231, p=0.032).


CONCLUSIONS
Our findings suggest that there is an association between anticholinergic drug use and cognitive decline in PD. This may provide an important opportunity for clinicians to avoid increasing progression of cognitive decline by avoiding drugs with AA. Increased awareness by clinicians is required about the classes of drugs that have anticholinergic properties.
Ehrt
Uwe
U
Stavanger University Hospital, Psychiatric Clinic, PO Box 1163, Hillevåg, 4095 Stavanger, Norway. uehr@sus.no
Broich
Karl
K
Larsen
Jan Petter
JP
Ballard
Clive
C
Aarsland
Dag
D
D000368:Aged; D000928:Antidepressive Agents / Q000009:adverse effects; D001921:Brain / Q000503:physiopathology; D018680:Cholinergic Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D003072:Cognition Disorders / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology*; D015331:Cohort Studies; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy* / Q000453:epidemiology* / Q000503:physiopathology; D015995:Prevalence; D012720:Severity of Illness Index
D000928:Antidepressive Agents; D018680:Cholinergic Antagonists