Neuroleptic Malignant Syndrome

Suppose you need to be prescribed antipsychotic drugs. You (or your loved ones) obviously hope that these drugs will have the desired effect. But for some, an even worse fate than a psychosis lies dormant.

Neuroleptic malignant syndrome is a potentially life-threatening idiosyncratic reaction to antipsychotic drugs characterized by fever, altered mental status, muscle rigidity, and autonomic dysfunction[1]. ‌The fever might result in hyperpyrexia, a condition where the body temperature goes above 41.5^o Celsius due to changes in the hypothalamus, the organ in the brain that regulates temperature.‌

The syndrome has been associated with virtually all neuroleptic drugs, including newer atypical antipsychotics, as well as a variety of other medications that affect central dopaminergic neurotransmission.

The first reported case of Neuroleptic Malignant Syndrome appeared in 1956, shortly after the introduction of the antipsychotic drug chlorpromazine (thorazine), which is primarily used to treat psychiatric disorders such as schizophrenia[2]. In the 60s, the medical world became increasingly worried and case studies started to appear regularly in journals[3].

Although uncommon, Neuroleptic Malignant Syndrome remains a critical consideration in the differential diagnosis of patients presenting with fever and mental status changes because it requires prompt recognition to prevent significant morbidity and death.

Treatment includes immediately stopping the offending drug and implementing supportive measures, as well as pharmacological interventions in more severe cases. Maintaining vigilant awareness of the clinical features of Neuroleptic Malignant Syndrome to diagnose and treat the disorder early, however, remains the most important strategy.

[1] Berman: Neuroleptic Malignant Syndrome in The Neurohospitalist – 2011
[2] Ayd: Fatal hyperpyrexia during chlorpromazine therapy in Journal of Clinical and Experimental Psychopathology – 1956
[3] Delay et al: Neuroleptique majeur non phénothiazine et non réserpine, l'halopéridol, dans le traitement des psychoses in Annales Médico-Psychologiques (Paris) - 1960