Posted by mtdewcmu on April 15, 2011, at 18:02:58
For all of the pharmacology geeks, I found this interesting. It seems some psych drugs inhibit cholinesterases to a significant degree, which would oppose any anticholinergic action. Celexa is one.
1. Am J Geriatr Pharmacother. 2011 Feb;9(1):80-7.
Potentially procholinergic effects of medications commonly used in older adults.
Rockwood K, Walsh R, Martin E, Darvesh S.
Department of Medicine (Divisions of Neurology and Geriatric Medicine), Dalhousie
University, Halifax, Nova Scotia, Canada.
BACKGROUND: Older adults are susceptible to a variety of illnesses, many of which
can be treated with medications that may need to be used for the long term.
Considerable attention has been paid to drugs that, in addition to their intended
function, may have an anticholinergic effect that results in undesirable side
effects, including impairment in cognition. Cholinesterase inhibitors are used as
procholinergic drugs to improve cognitive dysfunction in Alzheimer's disease. We
hypothesized that some of the drugs commonly used by older adults might, in
addition to their intended function, also have procholinergic effects by virtue
of inhibiting cholinesterases.
OBJECTIVE: To determine the potential procholinergic nature of some of the
commonly used drugs by examining their cholinesterase inhibiting properties.
METHODS: The Ellman spectrophotometric method was used with human
acetylcholinesterase and butyrylcholinesterase, in the absence and presence of
increasing concentrations of each test drug. To compare inhibition potencies,
from enzyme kinetic data, we determined half maximal inhibitory concentration
(IC(50) values) for each cholinesterase by each drug.
RESULTS: Of the 28 drugs examined, over half (17/28) inhibited one or both of the
human cholinesterases. The inhibition potencies were often within 1 to 2 orders
of magnitude of reversible cholinesterase inhibitors currently used to treat
Alzheimer's disease. These included trazodone, quetiapine, risperidone,
indapamide, and perindopril.
CONCLUSIONS: Many drugs used by older adults for other reasons have potentially
clinically relevant procholinergic effects. The effect of cumulative
cholinesterase inhibition merits clinical evaluation.
PMID: 21459311 [PubMed - in process]