The anticholinesterase activity of mefloquine

The characteristics of the inhibition of electric eel acetylcholinesterase (AChE) and horse serum butyrylcholinesterase (BChE) by the antimalarial agents mefloquine, chloroquine, amodiaquine and amopyroquine were determined. The antimalarials were found to be non-competitive inhibitors of both AChE and BChE. In both enzyme systems, inhibitory potencies were in the order amodiaquine greater than amopyroquine greater than chloroquine greater than mefloquine. The low inhibitory potency of mefloquine may account in part for the appearance of gastrointestinal and central nervous system disturbances only at high doses of the drug.