Two Cases of Levetiracetam-Induced Rhabdomyolysis With Low Levetiracetam Blood Concentrations

Levetiracetam is an antiepileptic drug used to treat tonic-clonic convulsions and partial seizures. In general, levetiracetam is well tolerated; however, rhabdomyolysis has been reported as a rare side effect. The underlying mechanism is unclear. This case report describes two cases of rhabdomyolysis during levetiracetam treatment for convulsive status epilepticus, both of whom developed rhabdomyolysis a few days after starting levetiracetam. When levetiracetam was replaced with lacosamide, creatinine kinase decreased to the normal range within approximately 10 days. Furthermore, blood levels of levetiracetam were measured at the onset of rhabdomyolysis, and the results suggest that its adverse effects may not be correlated with its levels in the blood. Monitoring creatinine kinase is important for early detection of levetiracetam-induced rhabdomyolysis.