EVALUATION OF RX 72601 AS AN ANTI-CURARE AGENT

RX 72601, a new and potent anticholinesterase, has been evaluated for its ability to reverse the neuromuscular blockade induced by non-depolarizing muscle relaxants. In rats RX 72601 10 jug/kg i.v. proved effective in reversing the effects of alcuronium, gallamine, pancuronium or tubocurarine and the drug exhibited a wide margin of safety. RX 72601 proved equally effective in reversing the effects of tubocurarine in both cats and baboons. In dogs and cats, effective anti-curare doses had little action on the cardiovascular or respiratory systems. Overall the results obtained indicate that RX 72601 may be a safe antagonist of non-depolarizing muscle relaxants and that it will be possible to use RX 72601 without prior administration of atropine. Non-depolarizing muscle relaxants are used com-monly during surgery to produce relaxation of skeletal muscles, and the ability of anticholin-esterase drugs to reverse this relaxation at the termination of surgery provides one of the principal clinical uses for anticholinesterases. In the majorit