Side effects
Sedation is very common, and extrapyramidal side effects are common and include restlessness, dystonic reactions, pseudoparkinsonism, and akathisia; the extrapyramidal symptoms can affect 2% of people at low doses, whereas higher doses may affect as many as 40% of people.Prochlorperazine can also cause a life-threatening condition called neuroleptic malignant syndrome (NMS). Some symptoms of NMS include high fever, stiff muscles, neck muscle spasm, confusion, irregular pulse or blood pressure, fast heart rate (tachycardia), sweating, abnormal heart rhythms (arrhythmias). Research from the Veterans Administration and United States Food and Drug Administration show injection site reactions. Adverse effects are similar in children. Warning
The FDA approved label for prochlorperazine includes a warning for increased risk of mortality in elderly patients with dementia related psychosis. Discontinuation
The British National Formulary recommends a gradual withdrawal when discontinuing antipsychotics to avoid acute withdrawal syndrome or rapid relapse. Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite. Other symptoms may include restlessness, increased sweating, and trouble sleeping. Less commonly there may be a feeling of the world spinning, numbness, or muscle pains. Symptoms generally resolve after a short period of time.There is tentative evidence that discontinuation of antipsychotics can result in psychosis. It may also result in reoccurrence of the condition that is being treated. Rarely tardive dyskinesia can occur when the medication is stopped. Pharmacology
Prochlorperazine is thought to exert its antipsychotic effects by blocking dopamine receptors.Prochlorperazine is analogous to chlorpromazine; both of these agents antagonize dopaminergic D2 receptors in various pathways of the central nervous system.
Research
Alexza Pharmaceuticals studied an inhaled form of prochlorperazine for the treatment of migraine through Phase II trials under the development name AT-001; development was discontinued in 2011. References
External links
"Prochlorperazine". Drug Information Portal. U.S. National Library of Medicine.