A serious adverse drug reaction probably induced by clonazepam: a case report of myotoxicity

BACKGROUND: The adverse drug reactions (ADRs) related to clonazepam are mild, and only two cases of myotoxicity induced by clonazepam have been reported, with both patients recovering well. We present a unique case of a serious ADR outcome after taking clonazepam. CASE PRESENTATION: A 24-year-old woman with a long-standing history of polio and a 2-year history of epilepsy developed a serious ADR after repeated exposure to oral clonazepam combined with sodium valproate that manifested as myotoxicity and elevated levels of creatine phosphokinase. The patient is currently bedridden and unable to take care of herself. CONCLUSION: Clinicians should be vigilant of the possibility of myotoxicity induced by clonazepam, especially in specific populations such as polio patients or when clonazepam is used in combination therapies.