Dados do Trabalho

Título

Phenytoin-induced rhabdomyolysis

RESUMO

Presentation of the Case
A 41-year-old male patient, previously hypertensive and diabetic, presented a sudden onset of two reentrant generalized tonic-clonic seizures, without regaining consciousness between them, with a total duration of about 10 minutes. In the initial evaluation in the emergency room, was in a typical post-ictal period, and initial assistance was provided and a loading dose of phenytoin with 20 mg/kg, was performed, and later maintained medication at a dose of 100 mg every eight hours. In laboratory tests on admission, the patient had Creatine phosphokinase (CK) of 311 U/L, creatinine 1.3 mg/dL. During hospitalization, an acute curve of CpK elevation was observed over the days, withpeak observed on the fourth day of hospitalization, in association with Acute Kidney Injury (AKI), with creatinine 5.7 mg/dL. In view of the expressive increase, in large proportion, in the context of a stable patient, without new crises, and without complaints, a hypothesis of association was raised the causal link between the rhabdomyolysis condition and the administration of phenytoin, with the drug being changed to Levetiracetam on fourth day of hospitalization (CK 20199 U/L). After this event, an immediate progressive drop in serum creatine phosphokinase levels was observed, so that and 24h after phenytoin suspension went to 14000.

Discussion
The causal association between phenytoin and rhabdomyolysis is considered rare, its first report being in 1976. In some cases, the manifestation and in a context of hypersensitivity syndrome, with other clinical and laboratory findings such as eosinophilia and skin rash, however, there are reports as being the only clinical manifestation, still considered with uncertain pathophysiology. In these cases, the diagnosis is a challenge, because rhabdomyolysis is a frequent finding in seizures. However, in view of being a complication often associated with acute kidney injury, it is important to evaluate differential diagnoses that require rapid management.

Final Comments
In this context, attention should be paid to this little-known adverse effect of the drug. Thus, acute elevations to unusual CK values, progressive worsening of AKI, and refractoriness to clinical measures to treat the condition should be considered warning signs for phenytoin-induced rhabdomyolysis. Since the response in these cases was observed soon after drug withdrawal, as seen in the case in question.

Palavras Chave

phenytoin
rhabdomyolysis
seizures