Can bromocriptine (Parlodel) be used to treat neuroleptic malignant syndrome?

Bromocriptine for Neuroleptic Malignant Syndrome

Yes, bromocriptine (Parlodel) can be used as an adjunctive pharmacologic treatment for neuroleptic malignant syndrome (NMS), particularly in severe cases, after immediate discontinuation of the offending antipsychotic and initiation of aggressive supportive care. 1

Treatment Algorithm for NMS

First-Line Management (Always Required)

• Immediately discontinue all antipsychotic medications and dopamine antagonists - this is the single most critical intervention 1, 2
• Provide aggressive supportive care including:
  • Benzodiazepines for agitation and to reduce muscle activity 1, 2
  • External cooling measures for hyperthermia 1, 2
  • IV fluids for dehydration and to prevent rhabdomyolysis 1
  • Intensive monitoring in an ICU setting (required for approximately 25% of patients) 1

Second-Line Pharmacologic Interventions (For Severe Cases)

Bromocriptine is indicated as a dopaminergic agent to address dopamine deficiency in severe NMS cases 1. The rationale is that NMS results from dopamine D2 receptor blockade in the CNS, and bromocriptine can help restore dopaminergic function 2.

• Multiple case series from the 1980s demonstrated successful treatment with bromocriptine, with dramatic improvement in symptoms and reduction in the previously reported 20% mortality rate 3, 4, 5
• Bromocriptine should be used in conjunction with supportive therapy, not as monotherapy 3
• Dantrolene sodium (a muscle relaxant) may also be used alongside bromocriptine to reduce muscle rigidity and hyperthermia 1, 5

Advanced Interventions (For Life-Threatening Presentations)

• Emergency sedation, neuromuscular paralysis, and intubation are required for extreme hyperthermia (>41.1°C) 1
• Electroconvulsive therapy (ECT) is recommended as a second-line treatment for severe and persistent NMS, particularly if the patient has a concurrent psychiatric condition that would benefit from ECT 1

Critical Monitoring Requirements

Monitor closely for life-threatening complications including:

• Rhabdomyolysis with elevated creatine kinase (median CK in documented cases is 2650 IU/L, ranging from 335 to 20,270 IU/L) 6
• Metabolic acidosis 1
• Renal failure (may require hemodialysis) 6
• Seizures 1
• Disseminated intravascular coagulation 1
• Hepatotoxicity and pulmonary edema 2

Laboratory monitoring should include: complete blood count, electrolytes, renal function, liver function, creatine kinase (peaks on day 2 after fever onset), arterial blood gases, and coagulation studies 1, 6

Important Caveats and Pitfalls

• Avoid physical restraints as they exacerbate isometric muscle contractions, worsening hyperthermia and lactic acidosis, thereby increasing mortality 1
• Avoid anticholinergics for routine prevention of extrapyramidal symptoms, as they may worsen autonomic instability 1
• Do not add metoclopramide (Reglan) or other dopamine antagonists in patients on antipsychotics, as this can precipitate or exacerbate NMS 2
• Bromocriptine efficacy remains somewhat controversial - while older case series showed benefit, it has been described as "alternatively considered without merit or efficacious" in more recent reviews 7

Prognosis with Treatment

With proper treatment including early use of bromocriptine and aggressive supportive care, mortality has decreased from 76% in the 1960s to less than 10-15% in recent years 1, 2. Symptoms typically resolve within days to weeks after discontinuation of the offending agent 2.