pancuronium (bromide hydrate)

Pancuronium is an aminosteroid antagonist of muscle-type nicotinic acetylcholine receptors (nAChRs) with an IC50value of 14.8 nM using patch clamp electrophysiology in BOSC23 cells expressing mouse nAChRs.1It acts as a non-depolarizing neuromuscular blocking agent.2Pancuronium enhances anesthesia induced by isoflurane , reducing immobilization with an ED50value of 1.62 μg/kg.3 1.Liu, M., and Dilger, J.P.Site selectivity of competitive antagonists for the mouse adult muscle nicotinic acetylcholine receptorMol. Pharmacol.75(1)166-173(2009) 2.Buckett, W.R., Marjoribanks, C.E., Marwick, F.A., et al.The pharmacology of pancuronium bromide (Org.NA97), a new potent steroidal neuromuscular blocking agentBr. J. Pharmacol. Chemother.32(3)671-682(1968) 3.Miyazaki, Y., Sunaga, H., Hobo, S., et al.Pancuronium enhances isoflurane anesthesia in rats via inhibition of cerebral nicotinic acetylcholine receptorsJ. Anesth.30(4)671-676(2016)

Tiotropium Bromide hydrate (BA-679 BR hydrate) is a potent anticholinergic and bronchodilator, serving as a muscarinic receptor antagonist, specifically targeting mAChR. It is developed for treating chronic obstructive airways disease (COPD), demonstrating novel and long-lasting effects. Binding studies with [3H]tiotropium bromide in human lung reveal its high potency and equivalent affinity for M1-, M2-, and M3-receptors, making it roughly 10 times more effective than ipratropium bromide. It notably inhibits cholinergic nerve-induced contraction of both guinea-pig and human airways more potently than atropine or ipratropium bromide, albeit with a slower onset. Tiotropium bromide uniquely presents slow dissociation from M3-receptors on airway smooth muscle and rapid dissociation from M2 autoreceptors on cholinergic nerve terminals. As a quaternary ammonium derivative, it shows high affinity and special kinetic selectivity towards muscarinic receptors across M1-, M2-, and M3-subtypes, due to its slower dissociation from M1- and M3-receptors compared to M2-receptors.