Pharyngeal spasticity due to dantrolene.

WHAT IS KNOWN AND OBJECTIVE: Dantrolene can be combined with baclofen to better treat spasticity, but may cause muscular weakness and dysphagia. We instead describe a pharyngeal spasm due to dantrolene. CASE SUMMARY: A 12-year-old male received dantrolene 3 mg/kg/day in adjunct to baclofen 2 mg/kg/day, to improve spasticity. After 5 days of full-dose dantrolene, his dysphagia worsened and he developed pharyngeal spasm. Dantrolene was suspected for an adverse reaction and removed. The patient subsequently improved. WHAT IS NEW AND CONCLUSION: Causality analysis determined a probable relationship between dantrolene and pharyngeal spasm. This may be due to direct muscle contraction by dantrolene, an effect seen previously in vitro.