text: NMS may also occur in people taking dopaminergic drugs (such as levodopa) for Parkinson's disease, most often when the drug dosage is abruptly reduced. In addition, other drugs with anti-dopaminergic activity, such as the antiemetic metoclopramide, can induce NMS. Tetracyclics with anti-dopaminergic activity have been linked to NMS in case reports, such as the amoxapines. Additionally, desipramine, dothiepin, phenelzine, tetrabenazine, and reserpine have been known to trigger NMS. Whether lithium can cause NMS is unclear. However, concomitant use of lithium is associated with a higher risk of NMS when the patient starts on a antipsychotic drug.
  At the molecular level, NMS is caused by a sudden, marked reduction in dopamine activity, either from withdrawal of dopaminergic agents or from blockade of dopamine receptors.
  Risk factors
  One of the clearest risk factors in the development of NMS is the course of drug therapy chosen to treat a condition. Use of high-potency antipsychotics, a rapid increase in the dosage of antipsychotics, and use of long-acting forms of antipsychotics (such as haloperidol)  are all known to increase the risk of developing NMS. There appears to be no relationship between duration of therapy and the development of NMS.
  Use of the following agents is most commonly associated with the development of NMS:
  Typical antipsychotics: e.g. haloperidol, chlorpromazine.
  Atypical antipsychotics: e.g. olanzapine, clozapine, risperidone
  Anti-dopaminergic antiemetics: e.g. droperidol
  Withdrawal of dopaminergic agents: e.g. levodopa, amantadine