From the Guidelines
Neuroleptic malignant syndrome (NMS) is a life-threatening neurological disorder caused by an adverse reaction to antipsychotic medications, characterized by fever, muscle rigidity, altered mental status, and autonomic instability, requiring immediate medical attention and discontinuation of the offending medication. The management of NMS involves primarily supportive care, including hydration, cooling measures, and monitoring of vital signs, as well as the removal of the initiating agent 1.
Key Characteristics of NMS
- Fever
- Muscle rigidity
- Altered mental status
- Autonomic instability, including tachycardia, blood pressure fluctuations, and sweating
- Dehydration or elevated creatine kinase and rhabdomyolysis may be treated with IV fluids 1
- Cardiorespiratory compromise may be managed with standard, supportive measures 1
Risk Factors and Incidence
The incidence of NMS has been estimated to range from 0.02% to 3%, with a mortality rate of less than 10% to 15% in recent years 2. Risk factors include:
- High-potency antipsychotics
- Rapid dose escalation
- Parenteral administration
- Dehydration
- Coadministration of psychotropic agents
- Preexisting organic brain disease
- Use of long-acting depot antipsychotics
Treatment and Management
The first step in management is to immediately discontinue the offending antipsychotic medication and provide supportive care. Specific pharmacological treatments may include benzodiazepines for agitation, as suggested by experts 1. Intensive care monitoring is often necessary, with attention to complications like rhabdomyolysis, renal failure, and electrolyte imbalances. After recovery, which typically takes 7-14 days, antipsychotics should be reintroduced cautiously, preferably using a different class with lower potency, and only after at least two weeks have passed since symptom resolution.
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 published literature has included some reports of Dantrium use in patients with Neuroleptic Malignant Syndrome (NMS). A syndrome resembling Neuroleptic Malignant Syndrome on abrupt withdrawal of bromocriptine mesylate
Neuroleptic Malignant Syndrome (NMS) is characterized by:
- Elevated temperature
- Muscular rigidity
- Altered consciousness
- Autonomic instability It may occur with rapid dose reduction, withdrawal of, or changes in antiparkinsonian therapy, or on abrupt withdrawal of certain medications, such as bromocriptine mesylate [3] [4].
From the Research
Definition and Characteristics of Neuroleptic Malignant Syndrome (NMS)
- Neuroleptic Malignant Syndrome (NMS) is a rare but life-threatening condition caused by dopamine modulating medications, particularly antipsychotics 5.
- NMS is characterized by fever, altered mental status, muscle rigidity, and autonomic dysfunction 6.
- It is a rare but potentially lethal form of drug-induced hyperthermia 7.
- The syndrome can occur in about 0.2% of patients treated with neuroleptics 8.
Risk Factors and Diagnosis
- Risk factors for NMS include previous episodes, dehydration, agitation, and the rate and route of neuroleptic administration 8.
- Patients with organic brain disorders or mood disorders, particularly when receiving lithium, may be at increased risk 8.
- Standardized criteria for the diagnosis of NMS have been developed and emphasize the classic findings of hyperthermia, muscle rigidity, mental status changes, and autonomic dysfunction 8.
Treatment and Management
- First-line treatments of neuroleptic malignant syndrome are supportive care, discontinuation of the offending agent, and pharmacotherapy 5.
- Treatment consists primarily of early recognition, discontinuation of triggering drugs, management of fluid balance, temperature reduction, and monitoring for complications 8.
- Use of dopamine agonists or dantrolene or both should be considered and may be indicated in more severe, prolonged, or refractory cases 8, 9.
- Electroconvulsive therapy has been used successfully in some cases and is particularly useful in the post-NMS patient 5, 8.