Mivacurium (chloride)

Mivacurium is an antagonist of nicotinic acetylcholine receptors (nAChRs) and muscarinic M₂ and M₃ receptors (ED₅₀s = 0.08, 0.3, and 0.1 mg/kg for ex vivo human skeletal muscle nAChRs, guinea pig cardiac M₂ receptors, and guinea pig bronchial M₃ receptors, respectively).¹ It inhibits acetylcholine-induced activation of neuronal nAChRs (IC₅₀s = 69.04, 3.71, 1.52, and 2.90 for human α3β2-, α3β4-, α4β2-, and α7-containing nAChRs expressed in Xenopus oocytes).² Mivacurium also inhibits adult human muscular α1β1εδ-containing nAChRs (IC₅₀ = 3.69 nM in Xenopus oocytes expressing the human recombinant receptor). In vivo, mivacurium inhibits bradycardia and bronchoconstriction induced by vagal stimulation or acetylcholine in guinea pigs.¹ It also induces neuromuscular blockade (ED₉₅ = 80 μg/kg) in sheep with a more rapid onset time than atracurium (Item No. 17796) and vecuronium (Item No. 15603).³ Formulations containing mivacurium have been used for pediatric anesthesia.⁴

WARNING This product is not for human or veterinary use.

1. Okanlami, O.A., Fryer, A.D., and Hirshman, C. Interaction of nondepolarizing muscle relaxants with M2 and M3 muscarinic receptors in guinea pig lung and heart. Anesthesiology 84(1), 155-161 (1996).

2. Johnsson, M., Gurley, D., Dabrowski, M., et al. Distinct pharmacologic properties of neuromuscular blocking agents on human neuronal nicotinic acetylcholine receptors: A possible explanation for the train-of-four fade. Anesthesiology 105(3), 521-533 (2006).

3. Clutton, R.E., and Glasby, M.A. A comparison of the neuromuscular and cardiovascular effects of vecuronium, atracurium and mivacurium in sheep. Res. Vet. Sci. 64(3), 233-237 (1998).

4. Zeng, R., Liu, X., Zhang, J., et al. The efficacy and safety of mivacurium in pediatric patients. BMC Anesthesiol. 17(1), 58 (2017).