What is the mechanism of action and use of Compazine (prochlorperazine)?

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From the Guidelines

Compazine (prochlorperazine) is a phenothiazine antipsychotic medication primarily used to treat nausea, vomiting, and vertigo, as well as psychotic disorders in some cases. It works by blocking dopamine receptors in the brain, specifically in the chemoreceptor trigger zone (CTZ) of the medulla, which helps prevent nausea and vomiting signals from reaching the vomiting center 1. For nausea and vomiting, the typical adult dose is 5-10 mg orally or 5-10 mg by intramuscular injection every 3-4 hours as needed, with a maximum daily dose of 40 mg, as seen in the guidelines for postoperative pain management 1. Common side effects include drowsiness, dizziness, blurred vision, dry mouth, and constipation. More serious adverse effects can include extrapyramidal symptoms (muscle stiffness, tremors), tardive dyskinesia with long-term use, and neuroleptic malignant syndrome in rare cases. Prochlorperazine should be used cautiously in elderly patients, those with cardiovascular disease, seizure disorders, or liver dysfunction, and should not be used in patients with severe central nervous system depression, bone marrow suppression, or those taking other CNS depressants without careful monitoring 1. Some key points to consider when using prochlorperazine include:

  • Monitoring for QTc prolongation, especially when coadministering with other medications that may prolong the QT interval 1
  • Avoiding use in patients with a history of QTc prolongation or torsades de pointes
  • Using the lowest effective dose and monitoring for signs of extrapyramidal symptoms or other adverse effects
  • Considering alternative treatments for nausea and vomiting, such as ondansetron or granisetron, especially in patients at high risk for adverse effects 1.

From the FDA Drug Label

For control of severe nausea and vomiting. For the treatment of schizophrenia. Prochlorperazine is effective for the short-term treatment of generalized non-psychotic anxiety.

  • Mechanism of Action: The exact mechanism of action of Compazine (prochlorperazine) is not explicitly stated in the label, but its uses include:
  • Control of severe nausea and vomiting
  • Treatment of schizophrenia
  • Short-term treatment of generalized non-psychotic anxiety
  • Key Uses: Compazine is used for the treatment of severe nausea and vomiting, schizophrenia, and short-term treatment of generalized non-psychotic anxiety 2

From the Research

Mechanism of Action

  • Compazine, also known as prochlorperazine, is a centrally acting dopamine receptor antagonist 3.
  • It works by blocking dopamine receptors in the brain, which helps to reduce nausea and vomiting 4.

Uses

  • Prochlorperazine is most commonly used for the treatment of nausea and vomiting 3.
  • It is often used to prevent opioid-induced nausea 5.
  • It can also be used to treat vomiting in the emergency department 4.
  • Additionally, it is used to treat uncomplicated nausea and vomiting in the emergency department 6.

Side Effects

  • Prochlorperazine can cause extrapyramidal reactions, such as akathisia, in susceptible patients 3, 5, 7.
  • Akathisia is a movement disorder characterized by a feeling of restlessness and a desire to move 7.
  • The incidence of extrapyramidal symptoms is higher with prochlorperazine compared to other antiemetics, such as perospirone 5.
  • Prochlorperazine can also cause sleepiness, but the incidence is lower compared to promethazine 6.

Comparison to Other Antiemetics

  • Prochlorperazine is more effective than promethazine for relieving symptoms of nausea and vomiting in the emergency department 6.
  • Prochlorperazine works faster and more completely than promethazine for uncomplicated nausea and vomiting 6.
  • Perospirone, an atypical antipsychotic, can be used as an alternative to prochlorperazine for preventing nausea and vomiting, with a lower incidence of extrapyramidal symptoms 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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