Dantrolene sodium, a drug used for malignant hyperthermia, does not reduce hyperthermia caused by MDMA or methamphetamine in rats and may increase lethality. In awake rats, moderate doses of MDMA or methamphetamine raised body temperature by more than 2.5 °C; intravenous dantrolene (6 mg/kg) after hyperthermia onset failed to lower brain, muscle, or skin temperatures, though it reduced movement. In a warm environment (29 °C) where MDMA caused severe hyperthermia (>40 °C) and death, dantrolene did not prevent lethality—all treated rats died during or after the session. The findings indicate dantrolene formulations are not suited to treat hyperthermia from these psychomotor stimulants.
A 28-year-old man transferred to a trauma center for suspected spinal cord injury after a fall was diagnosed with functional neurologic disorder after negative testing. His symptoms did not respond to nonsteroidal anti-inflammatory drugs or benzodiazepines. Intravenous subdissociative dose ketamine led to rapid symptom resolution and discharge. Subdissociative ketamine may be a safe, effective, and efficient therapy for acute FND exacerbations in the emergency department, though factors mediating outcomes need further study.