Effect of metrifonate on neuromuscular transmission.
The least detectable effect of acute cholinesterase inhibition (produced by edrophonium) in a normal subject is described. It consists of repetitive activity following the muscle response to a single nerve stimulus. Repetitive activity does not follow a second response at an interval of 30 msec. or 80 msec. There is no change in amplitude of the response to a single stimulus; nor to a second stimulus with the smallest dose of edrophonium. With higher doses of edrophonium the amplitude of the second response is reduced. 55 children were studied during treatment of urinary schistosomiasis with metrifonate (3 doses at 2 weekly intervals). No change in evoked muscle action potential amplitude attributable to treatment was detected. 3 children developed some repetitive activity 6 hours after their third dose, when erythrocyte cholinesterase inhibition was approximately 50%.
D000200:Action Potentials / Q000187:drug effects; D002648:Child; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D002802:Cholinesterases / Q000097:blood; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D009132:Muscles / Q000201:enzymology; D009469:Neuromuscular Junction / Q000187:drug effects*; D012552:Schistosomiasis / Q000188:drug therapy; D009435:Synaptic Transmission / Q000187:drug effects*; D014236:Trichlorfon / Q000494:pharmacology* / Q000627:therapeutic use
D002800:Cholinesterase Inhibitors; D014236:Trichlorfon; D002802:Cholinesterases