Succinylcholine, malignant hyperthermia and rhabdomyolysis
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* Alex Blais

In their presentation of a case of rhabdomyolysis possibly associated with mRNA SARS-CoV-2 vaccination, Salter and colleagues1 are to be commended for elucidating the relevant differential diagnosis, which includes neuroleptic malignant syndrome, serotonin syndrome and malignant hyperthermia. As the authors noted, correctly identifying a syndromic cause for rhabdomyolysis can help ensure both appropriate treatment and future risk mitigation. To this end, the authors compared and contrasted various characteristics of these syndromes in Table 2. However, a notable omission is the depolarizing muscle relaxant succinylcholine as an inciting agent for malignant hyperthermia.2

The pharmacogenetic disorder malignant hyperthermia is often mistakenly considered to fall solely within the purview of anesthesiology practice. Although this is generally accurate in the case of the potent volatile anesthetics, succinylcholine remains a muscle relaxant of choice for performing rapid sequence tracheal intubation outside of the operating room (e.g., in intensive care and emergency department settings). Given the article’s identification as a CPD article, it is particularly important to note that succinylcholine is a main causative agent for malignant hyperthermia alongside the potent volatile anesthetic agents.

## Footnotes

*   **Competing interests:** None declared.

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## References

1.  Salter B, Jessome M, Tarnopolsky M, et al. Possible association between rhabdomyolysis and mRNA SARS-CoV-2 vaccination in a patient with RYR1 gene mutation. CMAJ 2022;194:E252–6.
    
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2.  Visoiu M, Young MC, Wieland K, et al. Anesthetic drugs and onset of malignant hyperthermia. Anesth Analg 2014;118:388–96.
    
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