Quinidine Neuromuscular blockers

Drug Interactions Other antihypertensive agents Carbamazepine (vasodilators, ACE inhibitors, Rifampin diuretics, and beta-blockers) Phenobarbital Digoxin Cyclosporine Disopyramide Theophylline Flecainide Inhalation anesthetics Quinidine Neuromuscular blocking agents Cimetidine Lithium ... 

The effects of both depolarising neuromuscular blockers (e.g. suxamethonium (succinylcholine)) and competitive neuromuscular blockers (e.g. tubocurarine) can be increased by quinidine. Re-curarisation and apnoea have been seen in patients when quinidine was given during the recoveiy period from neuromuscular blockade. 

The interaction between quinidine and neuromuscular blockers is an established interaction of clinical importance, but the documentation is limited. The incidence is uncertain, but it was seen in one report cited to a greater or lesser extent in 5 of the 6 patients studied.- It has only been reported clinically with metocurine, tubocurarine and suxamethonium, but it occurs in animals with gallamine, and it seems possible that it could occur clinically with any depolarising or non-depolarising neuromuscular blocker. Be alert for increased neuromuscular blocking effects during and after surgery. 

The effect of administering different botulinum neurotoxin serotypes at the same time or within several months of each other is unknown. Excessive neuromuscular weakness may be exacerbated by administration of another botulinum toxin prior to the resolution of the effects of a previously administered botulinum toxin. Aminoglycosides Cautiously perform coadministration of botulinum toxin type A and aminoglycosides or other agents interfering with neuromuscular transmission (eg, curare-like nondepolarizing blockers, lincosamides, polymyxins, quinidine, magnesium sulfate, anticholinesterases, succinylcholine chloride) because the effect of the toxin may be potentiated. 

Quinidine is a non-depolarizing muscle blocker and potentiates the effects of neuromuscular blocking drugs (80). 

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