UMEM Educational Pearls

Neuroleptic malignant syndrome (NMS), which is similar in symptomatology to malignant hyperthermia (MH), is characterized by the following:
1) increased body temperature
2) muscle rigidity
3) altered mental status
4) autonomic instability
The difference between NMS and MH is the etiology.  NMS is caused by the following medications:
Antipsychotics (haldol, phenothiazines, clozapine, olanzapine, risperadone)
Antiemetics (metoclopramide, droperidol, prochlorperazine)
CNS stimulants (amphetamines, cocaine)
Other (lithium, TCA overdose)
NMS can also be cause by disconinuation of dopaminergic drugs (amantadine, bromocriptine, levodopa)
Symptoms can begin to appear 24 to 72 hours after the onset of drug therapy, and are usually gradual. 
Management includes checking CK level (>1000 distinguishes NMS from sepsis), immediate removal of the offending drug, and consideration of Dantrolene or Bromocriptine.


Marino P. The ICU Book. 3rd ed. Lippincott Marino P. The ICU Book. 3rd ed. Lippincott Williams & Wilkins, 2007:625-638.