Characterization of binding of antipsychotics to muscarinic receptors using mouse cerebral cortex

J Pharmacol Sci. 2019 Jun;140(2):197-200. doi: 10.1016/j.jphs.2019.05.006. Epub 2019 May 27.

Abstract

Antipsychotics are often the first-line treatment for behavioral and psychological symptoms of dementia. However, the potential anticholinergic effects of antipsychotics could counteract the therapeutic effects of cholinesterase inhibitors used to treat dementia. We investigated the inhibitory effects of 26 antipsychotics on [N-Methyl-3H]scopolamine specific binding in mouse cerebral cortex. At 10-5 M, chlorpromazine, levomepromazine, prochlorperazine, timiperone, zotepine, pimozide, blonanserin, olanzapine, quetiapine, and clozapine inhibited [N-Methyl-3H]scopolamine binding by > 45%. Furthermore, the pKi values of chlorpromazine, levomepromazine, zotepine, olanzapine, and clozapine overlapped with their clinically achievable blood concentrations. Therefore, the anticholinergic properties of these antipsychotics could attenuate the effects of cholinesterase inhibitors.

Keywords: Anticholinergic effect; Antipsychotics; Mouse cerebral cortex.

MeSH terms

  • Animals
  • Antipsychotic Agents / metabolism*
  • Antipsychotic Agents / pharmacology*
  • Cerebral Cortex / metabolism*
  • Chlorpromazine / pharmacology
  • Cholinergic Antagonists / metabolism*
  • Cholinesterase Inhibitors / metabolism*
  • Depression, Chemical
  • Drug Interactions
  • Male
  • Methotrimeprazine / pharmacology
  • Mice, Inbred Strains
  • Prochlorperazine / pharmacology
  • Protein Binding
  • Receptors, Muscarinic / metabolism*
  • Scopolamine / metabolism*

Substances

  • Antipsychotic Agents
  • Cholinergic Antagonists
  • Cholinesterase Inhibitors
  • Receptors, Muscarinic
  • Methotrimeprazine
  • Scopolamine
  • Chlorpromazine
  • Prochlorperazine