Succinylcholine is a depolarizing muscle relaxant used for urgent endotracheal intubation in the operating room, intensive care unit (ICU), and emergency department. The intravenous (IV) dose is 0.5 to 1.5 mg/kg. Time to effect is 1 minute and duration of action in patients with normal pseudocholinesterase activity is approximately 2 minutes with complete recovery in 5 minutes. If a working IV catheter is not available, succinylcholine may be given 3 to 4 mg/kg intramuscularly (IM) (maximum dose 150 mg) with an onset of 2 to 3 minutes. Muscle fasciculations will often be seen prior to complete muscle relaxation. Known side effects of succinylcholine are bradycardia and muscle pain.

Succinylcholine is indicated when rapid sequence induction is needed to quickly secure the airway with an endotracheal tube. Although succinylcholine may increase intracranial pressure, it can be used in patients with acute head trauma because the rapid onset, superior intubating conditions, and reversibility outweigh the risk associated with its use. Succinylcholine in lower doses is also used to treat laryngospasm.