Mivacron Mechanism of Action

Pharmacology: Pharmacodynamics: Mechanism of Action: Mivacurium is a highly selective, short-acting, non-depolarising neuromuscular blocking agent with a fast recovery profile.
Pharmacodynamic Effects: MIVACRON is a mixture of three mivacurium stereoisomers. The trans-trans and cis-trans stereoisomers comprise 92% to 96% of MIVACRON and when studied in cats their neuromuscular blocking potencies are not significantly different from each other or from mivacurium chloride. The cis-cis isomer has been estimated from studies in cats to have one-tenth of the neuromuscular blocking potency of the other two stereoisomers.
Pharmacokinetics: Metabolism: Enzymatic hydrolysis by plasma cholinesterase is the primary mechanism for inactivation of mivacurium and yields a quaternary alcohol and a quaternary monoester metabolite. Pharmacological studies in cats and dogs have shown that the metabolites possess insignificant neuromuscular, autonomic or cardiovascular activity at concentrations higher than seen in man.
The termination of the neuromuscular blocking action of MIVACRON is mainly dependent on hydrolysis by plasma pseudocholinesterase, which is present at high levels in human plasma.
Elimination: Multiple degradation/elimination pathways appear to exist for mivacurium (e.g. hydrolysis by liver esterases, elimination in bile and renal excretion).
Toxicology: Pre-Clinical Safety Data: Mutagenicity: Mivacurium has been evaluated in four short-term mutagenicity tests. Mivacurium was non-mutagenic in the Ames Salmonella assay, the mouse lymphoma assay, the human lymphocyte assay and the in vivo rat bone marrow cytogenetic assay.
Carcinogenicity: There is no information available on whether mivacurium has carcinogenic potential.