Why is succinylcholine not a great drug to use?

From the Guidelines

Succinylcholine is not a great drug to use due to its numerous serious adverse effects and contraindications, and safer alternatives like rocuronium should be considered instead. This neuromuscular blocking agent, while effective for rapid sequence intubation with its quick onset (30-60 seconds) and short duration (5-10 minutes), carries significant risks. It can cause potentially fatal hyperkalemia in patients with burns, crush injuries, neuromuscular disorders, or prolonged immobility, as noted in a study published in Pediatrics 1. Succinylcholine may trigger malignant hyperthermia in susceptible individuals, a life-threatening emergency requiring immediate treatment with dantrolene. The drug also causes fasciculations that can lead to myalgia, increases intraocular and intracranial pressure, and can produce bradycardia, especially with repeated doses. Additionally, patients with pseudocholinesterase deficiency may experience prolonged paralysis lasting hours instead of minutes.

Some of the key contraindications and precautions for succinylcholine use include:

• Patients with a history of malignant hyperthermia
• Severe burns or crush injuries
• Neuromuscular disease or myopathy
• Prolonged immobility
• Pseudocholinesterase deficiency

According to a more recent study published in the British Journal of Anaesthesia in 2018, rocuronium may be a more rational choice in critically ill patients, providing similar intubating conditions to succinylcholine with fewer side effects 1. Another study published in Anaesthesia in 2019 also suggests that rocuronium is a good alternative to succinylcholine, especially in cases where succinylcholine is contraindicated 1.

Overall, while succinylcholine can be effective for rapid sequence intubation, its potential risks and side effects make it a less desirable choice compared to safer alternatives like rocuronium, especially in patients with certain contraindications or precautions. The use of succinylcholine should be carefully considered and weighed against the potential benefits and risks, and alternative neuromuscular blocking agents should be used when possible.

From the FDA Drug Label

Succinylcholine should be administered with GREAT CAUTION to patients suffering from electrolyte abnormalities and those who may have massive digitalis toxicity, because in these circumstances succinylcholine may induce serious cardiac arrhythmias or cardiac arrest due to hyperkalemia Succinylcholine administration has been associated with acute onset of malignant hyperthermia, a potentially fatal hypermetabolic state of skeletal muscle. Succinylcholine is contraindicated in persons with personal or familial history of malignant hyperthermia, skeletal muscle myopathies and known hypersensitivity to the drug. Succinylcholine is not a great drug to use due to its potential to cause:

• Severe hyperkalemia, which may result in cardiac arrest, especially in patients with electrolyte abnormalities or massive digitalis toxicity 2
• Malignant hyperthermia, a potentially fatal hypermetabolic state of skeletal muscle 2
• Cardiac arrhythmias or cardiac arrest due to hyperkalemia 2 It is also contraindicated in patients with a personal or familial history of malignant hyperthermia or skeletal muscle myopathies 2

From the Research

Reasons for Limited Use of Succinylcholine

• Succinylcholine can cause hyperkalemia, a potentially life-threatening condition, especially in patients with certain medical conditions or those taking specific medications 3, 4, 5.
• The risk of hyperkalemia is higher in patients with elevated serum potassium levels, and succinylcholine may not be suitable for these patients 6, 7.
• Alternative neuromuscular blocking agents, such as rocuronium, may be safer and more effective in certain situations, with less risk of hyperkalemia 7.
• Succinylcholine can interact with other medications, such as beta-blockers, to increase the risk of hyperkalemia 3.
• Patients who have experienced trauma, have neuromuscular disease, or are infected may be more susceptible to the hyperkalemic effects of succinylcholine 4, 5.

Specific Patient Populations

• Trauma patients may be at higher risk for hyperkalemia due to tissue damage and other factors 4.
• Patients with sepsis or acute nonlymphoblastic leukemia may also be more susceptible to the hyperkalemic effects of succinylcholine 5.
• Children, especially those who are septic or immobilized, may be at higher risk for dangerous arrhythmias caused by succinylcholine 5.

Clinical Considerations

• A thorough medical history and evaluation of the patient's condition are essential before administering succinylcholine 6, 4.
• Alternative neuromuscular blocking agents should be considered in patients who are at high risk for hyperkalemia or other complications 7, 5.
• Close monitoring of serum potassium levels and cardiac function is crucial when using succinylcholine, especially in high-risk patients 3, 4, 5.