Which effect is associated with succinylcholine on skeletal muscle?

Which effect is associated with succinylcholine on skeletal muscle?

• A. Blunts cough
• B. Causes fasciculations (muscle twitching)
• C. Reduces intracranial pressure
• D. Improves oxygenation

Answer: (B)

Succinylcholine is a depolarizing neuromuscular blocker. It binds to nicotinic acetylcholine receptors at the motor endplate and mimics acetylcholine, causing an initial, widespread depolarization of the muscle membrane. That rapid depolarization triggers involuntary muscle contractions called fasciculations. After this brief phase, the endplate stays desensitized to further stimulation, producing flaccid paralysis. Fasciculations are the hallmark early effect on skeletal muscle with this drug, before paralysis sets in. The other listed effects aren’t characteristic of its action on skeletal muscle—succinylocholine does not primarily blunt cough, reduce intracranial pressure, or directly improve oxygenation.

Succinylcholine is a depolarizing neuromuscular blocker. It binds to nicotinic acetylcholine receptors at the motor endplate and mimics acetylcholine, causing an initial, widespread depolarization of the muscle membrane. That rapid depolarization triggers involuntary muscle contractions called fasciculations. After this brief phase, the endplate stays desensitized to further stimulation, producing flaccid paralysis. Fasciculations are the hallmark early effect on skeletal muscle with this drug, before paralysis sets in. The other listed effects aren’t characteristic of its action on skeletal muscle—succinylocholine does not primarily blunt cough, reduce intracranial pressure, or directly improve oxygenation.