Neuroleptic malignant syndrome is a rare but potentially life-threatening reaction to the use of almost any of a group of antipsychotic drugs or major tranquilizers (neuroleptics). These drugs are commonly prescribed for the treatment of schizophrenia and other neurological, mental, or emotional disorders. Several of the more commonly prescribed neuroleptics include thioridazine, haloperidol, chlorpromazine, fluphenazine and perphenazine.
The syndrome is characterized by high fever, stiffness of the muscles, altered mental status (paranoid behavior), and autonomic dysfunction. Autonomic dysfunction alludes to defective operations of the components of the involuntary (autonomic) nervous system, leading to wide swings of blood pressure, excessive sweating and excessive secretion of saliva.
A genetic basis for the disorder is suspected but not proven. It does appear to be clear that a defect in the receptors to dopamine (dopamine D2 receptor antagonism) is an important contributor to the cause of neuroleptic malignant syndrome.