Rinsho Shinkeigaku (Clinical Neurology)

Brief Clinical Note

A case of myasthenia-like symptoms induced by cibenzoline overdosage

Yoshihiro Nakagawa1)3), Masatoshi Ishizaki, M.D.2), Aki Kozono3), Kiyonori Hanada3), Toshinobu Higashi4) and Hidetsugu Ueyama, M.D.2)

1)Department of Pharmacy, National Hospital Organization Kumamoto Medical Center
2)Department of Neurology, Kumamoto Saishunso National Hospital
3)Department of Pharmacy, Kumamoto Saishunso National Hospital
4)Department of Cardiology, Kawaguchi Hospital

The present patient was an 87-year-old man who had been taking cibenzoline for tachyarrhythmia. Five years after initiation of administration, he was referred to our hospital for ptosis that worsened from midday, as well as weakness of the facial and limb muscles. He tested negative for anti-acetylcholine receptor antibody but positive in the edrophonium test, suggesting that he had myasthenia gravis. He was admitted to our hospital 3 years later due to worsening symptoms of ptosis and muscle weakness. He had hypoglycemia, cardiac conduction defect, and renal dysfunction. In addition, blood concentration of cibenzoline was markedly high (1,850 ng/ml). We terminated the administration of cibenzoline, after which the patient's neurologic symptoms improved. Our findings suggest that cibenzoline toxicity must be considered in differentiating myasthenia gravis when a patient also presents with renal dysfunction.
Full Text of this Article in Japanese PDF (376K)

(CLINICA NEUROL, 58: 41|44, 2018)
key words: myasthenia gravis, cibenzoline toxicity, therapeutic drug monitoring

(Received: 16-Jun-17)