Neuroleptic malignant syndrome: guidelines for treatment and reinstitution of neuroleptics.

The neuroleptic malignant syndrome (NMS) is a dangerous, often fatal, idiosyncratic disorder presumably of the basal ganglia and hypothalamus. It is usually associated with neuroleptic medications, and it is believed to be related to blockage of dopamine receptors in the brain. The NMS has also been reported in patients with Parkinson's disease after withdrawal of antiparkinsonian agents during "drug holidays." Cardinal features include fever, muscular rigidity, an elevated serum level of creatine phosphokinase, changes in mental status, and autonomic dysfunction. Although treatment has been largely supportive, dopamine agonists, such as bromocriptine, and a direct-acting muscle relaxant, dantrolene, have been used with good clinical outcome. Guidelines for reinstitution of neuroleptics are suggested.