Weak inhibitors protect cholinesterases from strong inhibitors (paraoxon): in vitro effect of tiapride

Weak and reversible inhibitors of cholinesterases, when administered before potent organophosphorus inhibitors (pretreatment), have the ability, to a certain extent, to protect enzymes from inhibition. Such a protective effect was demonstrated in vitro for metoclopramide and ranitidine. The putative mode of protective action of these substances is, when administered in excess, competition for the active site of the enzyme with the more potent organophosphate. The present paper presents results using another benzamide with weak cholinesterase inhibitory properties: tiapride (TIA).