Pancuronium (dibromide)

Pancuronium dibromide, a bis-quaternary steroid, is a neuromuscular relaxant. Pancuronium dibromide inhibits neuromuscular transmission by competing with acetylcholine for binding sites on nACh receptors. Pancuronium dibromide also inhibits cardiac muscarinic receptors and has a sympathomimetic action^[1][2][3]. In Vitro:The action of Pancuronium on transmembrane sodium conductance is investigated in dorsal root ganglion neurones of chick embryos. Externally perfused Pancuronium (50 μM to 1 mM) reversibly inhibits the current by a fast mechanism of action. Inhibition is concentration-dependent (with a half-effective dose of 170 μM) but not voltage-dependent. Pancuronium may reduce the sodium current by interacting with the sodium channels in both the resting and open states^[2]. In Vivo:Pancuronium (0.5 mg/kg; intravenous injection) abolishes the bradycardia induced both by injected acetylcholine (ACh) and by vagal nerve stimulation in guinea-pigs (250-300 g, male). At doses which produce 100% neuromuscular blockade, Pancuronium (0.04 mg/kg) potentiates vagally-induced bronchoconstriction^[1].
Potentiation by Pancuronium of the effects of adrenergic nerve stimulation, is found in rat anococcygeus and vas deferens^[3].