Neuroleptic malignant syndrom is a rare but serious complication, similar to the malignant hypertermia syndrom seen with certain anesthetics. It occurs in 1% to 2% of patients and is fatal in almost 10% of those affected. This is observed early in treatment and is characterized by a near complete collapse of the autonomic nervous system, causing, for example, fever, muscle rigidity, diaphoresis, mental confusion and cardiovascular instability. Immediate medical intervention with bromcriptine (DA agonist) and dantrolene is nessesary.