Dantrolene

Snapshot

  • A 31-year-old woman with a medical history of schizophrenia is brought to the emergency department by her husband due to agitation, confusion, and delirium. Her temperature is 104°F (40°C), blood pressure is 162/108 mmHg, pulse is 110/min, and respirations are 31/min. On physical examination, she is diaphoretic, with generalized muscular rigidity. Laboratory testing is significant for a creatine kinase level of 4,680 IU/L. Her antipsychotic is removed, and supportive care is initiated. She is started on dantrolene for management of neuroleptic malignant syndrome.

Introduction

  • Mechanism of action
    • blocks ryanodine receptors
      • decreases excitation-contraction coupling
      • decreases Ca2+ release from the sarcoplasmic reticulum in skeletal muscle
  • Clinical use
    • malignant hyperthermia 
      • hypermetabolic crisis secondary to inhaled anesthetic use (e.g., halothane) or succinylcholine
        • patients have a genetic abnormality in ryanodine or dihydropyridine receptors, a skeletal muscle protein
          • results in excessive Ca2+ release from the sarcoplasmic reticulum
    • neuroleptic malignant syndrome (NMS)
      • medical emergency secondary to neuroleptic use (e.g., antipsychotics)
        • characterized by
          • hyperthermia
          • mental status change
          • rigidity
          • autonomic dysfunction