What muscle relaxants are safe to administer in a patient with a rocuronium (Zemuron) allergy, and does succinylcholine (suxamethonium) exhibit cross-reactivity?

From the Guidelines

For patients with a rocuronium allergy, cisatracurium is generally considered the safest alternative muscle relaxant due to its minimal histamine release and unique metabolism through Hofmann elimination, which occurs independently of liver or kidney function. This recommendation is based on the fact that cisatracurium has a distinct chemical structure and mechanism of action compared to other non-depolarizing muscle relaxants, which reduces the risk of cross-reactivity 1. Other potential options include vecuronium, pancuronium, and atracurium, though these carry varying degrees of cross-reactivity risk.

When considering alternative muscle relaxants, it's essential to note that suxamethonium (succinylcholine) does not typically demonstrate cross-reactivity with rocuronium as it belongs to a different chemical class (depolarizing versus non-depolarizing agents) and has a distinct mechanism of action 1. However, caution is still warranted as some patients with multiple drug allergies may show unpredictable reactions.

Key considerations for managing patients with a rocuronium allergy include:

• Having emergency medications readily available (epinephrine, antihistamines, corticosteroids)
• Considering pretreatment with H1 and H2 blockers in high-risk cases
• Individualizing the choice of alternative muscle relaxant based on the patient's medical history, the severity of their previous reaction to rocuronium, and the specific requirements of the procedure
• Being aware of the potential for cross-reactivity between different muscle relaxants, particularly those with similar chemical structures or mechanisms of action 1.

From the Research

Muscle Relaxants Safe to Give in a Patient with a Rocuronium Allergy

• Cisatracurium had the lowest prevalence of cross-reactivity in patients with known anaphylaxis to rocuronium or vecuronium 2
• Pancuronium and vecuronium are considered low-risk agents for allergy compared to rocuronium 3
• In patients with a rocuronium allergy, skin testing and basophil activation test (BAT) can help identify cross-reactivity with other neuromuscular blocking agents, such as vecuronium 4

Cross-Reactivity of Suxamethonium with Rocuronium

• Suxamethonium has a high risk of triggering anaphylaxis and cross-reactivity with rocuronium 2
• Skin tests were performed with rocuronium, suxamethonium, and other neuromuscular blocking agents to diagnose cross-reactivity in patients with a known allergy to a muscle relaxant 5
• The study found that 30 out of 31 patients had cross-reactivity with other neuromuscular blocking agents, including suxamethonium 5

Alternative Muscle Relaxants

• Cisatracurium may be a safe alternative for patients with a rocuronium allergy due to its low cross-reactivity 2, 6
• Early skin and challenge testing can help identify a safe neuromuscular blocking drug for subsequent surgery in patients with a recent anaphylactic reaction to rocuronium 6