Anticholinergic activity of 107 medications commonly used by older adults.
The objective of this study was to measure the anticholinergic activity (AA) of medications commonly used by older adults. A radioreceptor assay was used to investigate the AA of 107 medications. Six clinically relevant concentrations were assessed for each medication. Rodent forebrain and striatum homogenate was used with tritiated quinuclidinyl benzilate. Drug-free serum was added to medication and atropine standard-curve samples. For medications that showed detectable AA, average steady-state peak plasma and serum concentrations (C(max)) in older adults were used to estimate relationships between in vitro dose and AA. All results are reported in pmol/mL of atropine equivalents. At typical doses administered to older adults, amitriptyline, atropine, clozapine, dicyclomine, doxepin, L-hyoscyamine, thioridazine, and tolterodine demonstrated AA exceeding 15 pmol/mL. Chlorpromazine, diphenhydramine, nortriptyline, olanzapine, oxybutynin, and paroxetine had AA values of 5 to 15 pmol/mL. Citalopram, escitalopram, fluoxetine, lithium, mirtazapine, quetiapine, ranitidine, and temazepam had values less than 5 pmol/mL. Amoxicillin, celecoxib, cephalexin, diazepam, digoxin, diphenoxylate, donepezil, duloxetine, fentanyl, furosemide, hydrocodone, lansoprazole, levofloxacin, metformin, phenytoin, propoxyphene, and topiramate demonstrated AA only at the highest concentrations tested (patients with above-average C(max) values, who receive higher doses, or are frail may show AA). The remainder of the medications investigated did not demonstrate any AA at the concentrations examined. Psychotropic medications were particularly likely to demonstrate AA. Each of the drug classifications investigated (e.g., antipsychotic, cardiovascular) had at least one medication that demonstrated AA at therapeutic doses. Clinicians can use this information when choosing between equally efficacious medications, as well as in assessing overall anticholinergic burden.
Chew
Marci L
ML
Department of Pharmaceutical Sciences, School of Pharmacy, Geriatric Psychopharmacology Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Mulsant
Benoit H
BH
Pollock
Bruce G
BG
Lehman
Mark E
ME
Greenspan
Andrew
A
Mahmoud
Ramy A
RA
Kirshner
Margaret A
MA
Sorisio
Denise A
DA
Bies
Robert R
RR
Gharabawi
Georges
G
D000368:Aged; D002800:Cholinesterase Inhibitors / Q000009:adverse effects* / Q000145:classification / Q000493:pharmacokinetics; D003072:Cognition Disorders / Q000139:chemically induced*; D005260:Female; D005853:Geriatrics; D006801:Humans; D008297:Male; D008954:Models, Biological; D014018:Tissue Distribution
D002800:Cholinesterase Inhibitors