NEUROLEPTIC MALIGNANT SYNDROME: A REVIEW

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal complication associated with the use of neuroleptic drugs. It is a life-threatening neurologic emergency associated with the use of dopamine antagonists, and less commonly with dopamine agonist withdrawal. It occurs with 0.2 % of patients with neuroleptics. First-generation antipsychotic agents are most commonly implicated, but NMS can occur with any antipsychotic agent and also with antiemetic drugs. It presents with the tetrad of clinical features hyperthermia, muscle rigidity, mental status changes, and autonomic dysfunction. Risk factors of NMS include Previous episodes, dehydration, agitation, and the rate and route of neuroleptic administration. Patients with psychiatric illness or mood disorders, especially those on lithium, may be at higher risk for NMS despite the fact that it has been reported in patients with diverse psychiatric diagnoses as well as in normal patients. Important considerations in the differential diagnosis include meningitis, encephalitis, systemic infections, heat stroke, and other drug-induced dysautonomias. The syndrome lasts for 7 to 10 days in uncomplicated cases receiving oral neuroleptics. The treatment mainly consists of early recognition, discontinuation of triggering drugs, management of fluid balance, temperature reduction, and monitoring for complications.  Use of dopamine agonists (eg. bromocriptine, amantadine) or dantrolene or both should be considered in treating in more severe, prolonged, or refractory cases. Electroconvulsive therapy (ECT) is an option in patients not responding to drug treatment in the first week, those with residual catatonia persists after other symptoms have resolved, and those in whom lethal catatonia is suspected as an alternative or concomitant disorder. it has been used successfully in the post-NMS patients. As a result of these measures, mortality from NMS has reduced in recent years although fatalities still occur. In the majority of patients who have recovered from an NMS episode, neuroleptics may be safely reintroduced. The lack of knowledge regarding NMS may delay the onset of therapy, impair the quality of treatment, and lead to a worse outcome or even cause death.

KEYWORDS: Neuroleptic Malignant Syndrome, Dopamine antagonist, Hyperthermia, Dantrolene, Electroconvulsive therapy