Severe Recurrence of Neuroleptic Malignant Syndrome: Usefulness of Dexmedetomidine for Antipsychotic Withdrawal

Neuroleptic malignant syndrome (NMS) is a potentially fatal side effect that occurs in patients taking antipsychotics. Patients with NMS are often forced to rechallenge antipsychotic medications to control the underlying psychiatric symptoms. We present a case of severe recurrence of NMS in a patient in whom the administration of antipsychotics was restarted two days after NMS resolution. A 19-year-old man with somatic symptom disorder had been transported for fever, tachycardia, rigidity, and disturbance of consciousness. He was taking atypical antipsychotics with poor medication compliance. A diagnosis of NMS was made, and he was treated with administration of dantrolene sodium and benzodiazepines under tracheal intubation. On day 2, he was extubated. On day 4, his symptoms of NMS improved, but psychiatric symptoms rapidly exacerbated. He and his family strongly insisted on discharge, and we therefore unavoidably restarted the administration of antipsychotics. On day 37, he was retransported, and a diagnosis of recurrence of NMS was made. Blood examination showed marked deterioration of acute kidney injury and disseminated intravascular coagulation compared to those at the first admission. Without the administration of antipsychotics, his psychiatric symptoms were poorly controlled. Administration of dexmedetomidine helped his agitation to be well controlled without antipsychotics for two weeks. Short-term restart of antipsychotic drugs in patients with NMS may result in more severe NMS relapse. Dexmedetomidine may be useful for NMS patients when the administration of antipsychotics cannot be restarted. When antipsychotics are unavoidably rechallenged in patients with NMS, the risk of severe relapse should be taken into consideration, and dexmedetomidine may be used for prolongation of the withdrawal period.