Localized muscle spasm as a manifestation of pembrolizumab-induced infusion reaction

As immune checkpoint inhibitors increasingly gain oncological utility, the incidence of unique adverse events may rise as well. The description and management of localized, recurrent muscle spasms secondary to pembrolizumab infusions has not previously been reported.

A 64-year-old male receiving pembrolizumab infusions experienced acute-onset, isolated spasms and pain occurring in cycles 2 through 5.Management and outcome: Pretreatment with intravenous lorazepam, diphenhydramine, famotidine, ondansetron, and fluids have led to spasm-free pembrolizumab infusions.

The purpose of this report is to provide the first known incidence and successful corrective measures taken for localized muscle spasms secondary to pembrolizumab infusion.