Neuromuscular Blockers Quiz

Which of the following drugs is a nondepolarizing neuromuscular blocker:

• Succinylcholine

• Vecuronium

• Decamethonium

• Dantrolene sodium

The site of action of d-tubocurarine is:

• Spinal internuncial neurone

• Motor nerve ending

• Muscle end-plate

• Sodium channels in the muscle fibre

At the muscle end-plate, d-tubocurarine reduces the:

• Number of Na+ channels

• Duration for which the Na+ channels remain open

• Ion conductance of the open Na+ channel

• Frequency of Na+ channel opening

Select the skeletal muscle relaxant that is commonly used for endotracheal intubation despite causing histamine release, K+ efflux from muscles and cardiovascular changes:

• Pipecuroniun

• Succinylcholine

• Pancuronium

• Cisatracurium

Neuromuscular blocking drugs do not produce central actions because:

• They do not cross the blood-brain barrier

• Nicotinic receptors are not present in the brain

• They are sequestrated in the periphery by tight binding to the skeletal muscles

• They do not ionise at the brain pH

Pancuronium differs from tubocurarine in that:

• It is a depolarizing blocker

• Its action is not reversed by neostigmine

• It can cause rise in BP on rapid I.V. injection

• It causes marked histamine release

Which of the following drugs undergoes 'Hofmann' elimination:

• Succinylcholine

• Pancuronium

• Vecuronium

• Atracurium

The most rapidly acting nondepolarizing neuromuscular blocking agent which can be used as an alternative to succinylcholine for tracheal intubation is:

• Rocuronium

• Pancuronium

• Doxacurium

• Pipecuronium

Succinylcholine is the preferred muscle relaxant for tracheal intubation because:

• It does not produce postoperative muscle soreness

• It does not alter heart rate or blood pressure

• It does not cause histamine release

• It produces rapid and complete paralysis of respiratory muscles with quick recovery

Which of the following is applicable to mivacurium:

• It undergoes Hoffmann elimination

• It is the shortest acting nondepolarizing neuromuscular blocker

• It is excreted unchanged by kidney

• It does not cause histamine release