indication

For use as an anesthesia adjunct to induce skeletal muscle relaxation and to reduce the intensity of muscle contractions in convulsive therapy.

pharmacology

Metocurine iodide is a benzylisoquinolinium competitive nondepolarizing neuromuscular blocking agent. Metocurine iodide has a moderate risk of inducing histamine release and has some ganglion blocking activity. Metocurine iodide can be used most advantageously if muscle twitch response to peripheral nerve stimulation is monitored to assess degree of muscle relaxation. As with other nondepolarizing neuromuscular blockers, the time to onset of paralysis decreases and the duration of maximum effect increases with increasing doses of metocurine iodide. Repeated administration of maintenance doses of metocurine iodide has no cumulative effect on the duration of neuromuscular block if recovery is allowed to begin prior to repeat dosing. Moreover, the time needed to recover from repeat doses does not change with additional doses. Repeat doses can therefore be administered at relatively regular intervals with predictable results.

mechanism of action

Metocurine iodide antagonizes the neurotransmitter action of acetylcholine by binding competitively with cholinergic receptor sites on the motor end-plate. This antagonism is inhibited, and neuromuscular block reversed, by acetylcholinesterase inhibitors such as neostigmine, edrophonium, and pyridostigmine.

toxicity

Excessive doses can be expected to produce enhanced pharmacological effects. Overdosage may increase the risk of histamine release and cardiovascular effects, especially hypotension.

half life

3 to 4 hours