Last reviewed 01/2018

Pseudocholinesterase describes a family of enzymes produced mainly in the liver but widely found in:

  • plasma
  • liver
  • skin
  • gastrointestinal tract

It hydrolyses esters e.g. procaine and suxamethonium. It can occur as a number of variants, dependent on four alleles, with variable degrees of cholinesterase function. The nature of the variants determines sensitivity to suxamethonium; the extreme is pseudocholinesterase deficiency.

Pseudocholinesterases are irreversibly inhibited by organophosphate compounds; the reduction in plasma activity is a means of monitoring exposure of individuals to organophosphates.