What are the medications that can cause Neuroleptic Malignant Syndrome (NMS) in the Emergency Department (ED)?

From the Guidelines

Neuroleptic Malignant Syndrome (NMS) in the emergency department should be treated immediately with supportive care and specific medications, prioritizing discontinuation of the offending antipsychotic medication and administration of dantrolene sodium and bromocriptine. When managing NMS, it is crucial to consider the potential side effects of antipsychotic medications, as discussed in the study by 1. The use of atypical antipsychotic agents, such as risperidone, may be associated with a lower risk of extrapyramidal side effects compared to traditional antipsychotics. However, the primary concern in the emergency department is the prompt recognition and treatment of NMS.

Key considerations in the management of NMS include:

• Discontinuation of the offending antipsychotic medication
• Administration of dantrolene sodium, typically given at 1-2.5 mg/kg IV every 6 hours (maximum 10 mg/kg daily) until symptoms resolve
• Administration of bromocriptine, a dopamine agonist, at 2.5-10 mg orally three times daily for 7-10 days
• Use of benzodiazepines, such as lorazepam, to manage agitation and rigidity
• Aggressive cooling measures for hyperthermia, IV fluids for dehydration, and cardiac monitoring as essential supportive measures

The study by 1 provides guidance on the management of delirium symptoms in adult patients, including the use of antipsychotic medications and benzodiazepines. However, in the context of NMS, the primary focus is on the immediate discontinuation of the offending medication and the administration of specific treatments, such as dantrolene sodium and bromocriptine. The study by 1 discusses the use of benzodiazepines and antipsychotic medications in the management of agitation in adult patients, but this is not directly applicable to the management of NMS.

In summary, the management of NMS in the emergency department requires prompt recognition and treatment, prioritizing discontinuation of the offending antipsychotic medication and administration of dantrolene sodium and bromocriptine, as supported by the study by 1.

From the FDA Drug Label

A symptom complex resembling the neuroleptic malignant syndrome (characterized by elevated temperature, muscular rigidity, altered consciousness, and autonomic instability), with no other obvious etiology, has been reported in association with rapid dose reduction, withdrawal of, or changes in antiparkinsonian therapy The FDA drug label mentions a symptom complex resembling Neuroleptic Malignant Syndrome (NMS) in association with rapid dose reduction, withdrawal, or changes in antiparkinsonian therapy, including bromocriptine mesylate.

• Key symptoms of NMS include:
  • Elevated temperature
  • Muscular rigidity
  • Altered consciousness
  • Autonomic instability In the context of the ED, it is essential to be aware of these potential symptoms when managing patients on bromocriptine mesylate or other antiparkinsonian medications 2.

From the Research

NMS Medications in the ED

• NMS is a rare but potentially fatal complication of antipsychotic drug therapy, characterized by hyperthermia, rigidity, autonomic disturbances, and altered consciousness 3, 4.
• The combination of dantrolene and post-synaptic dopamine agonists, such as bromocriptine, may be effective in treating NMS 3.
• Other treatments that have been used effectively in the treatment of NMS include amantadine, carbidopa/levodopa, and electroconvulsive therapy 4, 5.
• Early identification and treatment of NMS are crucial to improve patient outcomes, particularly in high-risk populations such as trauma patients 6, 7.
• Specific NMS therapies, including dantrolene, bromocriptine, and electroconvulsive therapy, may be superior to symptomatic therapy in severe cases of NMS 5.

Treatment Options

• Dantrolene: a peripheral muscle relaxant that has been shown to be effective in treating NMS 3, 4, 5.
• Bromocriptine: a dopamine agonist that has been used to treat NMS, particularly in combination with dantrolene 3, 4, 5.
• Electroconvulsive therapy: a treatment option that has been shown to be effective in severe cases of NMS 5.
• Amantadine: a dopamine agonist that has been used to treat NMS, although its effectiveness is less well-established than that of bromocriptine and dantrolene 3, 4.
• Carbidopa/levodopa: a dopamine agonist that has been used to treat NMS, although its effectiveness is less well-established than that of bromocriptine and dantrolene 3.