Prochlorperazine

1. Introduction

Prochlorperazine is a phenothiazine derivative used primarily for managing nausea, vomiting, and dizziness associated with various conditions, including migraines and vertigo. It also has antipsychotic properties and is sometimes prescribed for short-term management of psychotic disorders. Prochlorperazine works by blocking dopamine receptors in the brain, particularly in the chemoreceptor trigger zone, to reduce nausea and vomiting.

2. Indications

  • Nausea and vomiting (due to chemotherapy, post-operative, or other causes)
  • Vertigo associated with Ménière’s disease or vestibular disorders
  • Migraine (for nausea and associated symptoms)
  • Short-term management of acute psychosis or agitation
  • Anxiety (short-term use when other treatments are unsuitable)

3. Dosage

Adults:

  • Nausea and vomiting: 5–10 mg 2–3 times daily (maximum: 40 mg/day).
  • Migraine-associated nausea: 3–6 mg as buccal tablets twice daily.
  • Acute psychosis: 12.5–25 mg intramuscularly, repeated in 6 hours if needed.
  • Vertigo: 5 mg 3 times daily, adjustable based on response.

Children (>10 kg or >2 years):

  • Nausea and vomiting: 0.25 mg/kg 2–3 times daily (maximum: 10 mg/day).

Elderly:

  • Start at the lower end of the dosing range due to increased sensitivity to side effects.

4. Administration

  • Take orally with water, with or without food.
  • Buccal tablets should be placed between the gum and cheek and allowed to dissolve.
  • Intramuscular injections should be administered by a healthcare professional.

5. Forms Available

  • Tablets: 5 mg, 10 mg
  • Buccal tablets: 3 mg
  • Oral syrup: 5 mg/5 mL
  • Injection: 12.5 mg/mL

6. Side Effects

6.1 Common Side Effects:

  • Drowsiness
  • Dizziness
  • Dry mouth
  • Blurred vision
  • Constipation

6.2 Less Common Side Effects:

  • Weight gain
  • Hypotension
  • Restlessness (akathisia)

6.3 Rare but Serious Side Effects:

  • Extrapyramidal symptoms (e.g., dystonia, tremor)
  • Neuroleptic malignant syndrome (NMS)
  • Tardive dyskinesia (involuntary movements)
  • Severe allergic reactions (e.g., anaphylaxis)

7. Warnings

  • Extrapyramidal Symptoms (EPS): Risk of movement disorders, particularly in children and elderly patients.
  • Neuroleptic Malignant Syndrome (NMS): Rare but potentially fatal condition; discontinue immediately if symptoms occur (e.g., fever, muscle rigidity, altered mental status).
  • CNS Depression: Avoid use with other sedatives, as it may enhance CNS depression.

8. Precautions

  • Use cautiously in patients with Parkinson’s disease, as it may worsen symptoms.
  • Avoid in patients with narrow-angle glaucoma or prostatic hypertrophy.
  • Monitor patients with a history of seizures, as it may lower the seizure threshold.

9. Interactions

  • CNS depressants (e.g., opioids, alcohol): Increased sedation and respiratory depression.
  • Anticholinergics: Increased risk of side effects like dry mouth and constipation.
  • Levodopa: Reduced effectiveness due to dopamine receptor antagonism.
  • Antihypertensives: Enhanced hypotensive effects.

10. Monitoring Parameters

  • Monitor for improvement in nausea, vomiting, or vertigo symptoms.
  • Assess for signs of extrapyramidal symptoms or tardive dyskinesia, especially with prolonged use.
  • Observe for signs of sedation, hypotension, or neuroleptic malignant syndrome.

11. Use in Children

  • Safe for children >10 kg or >2 years when used at appropriate doses. Monitor closely for extrapyramidal side effects.

12. Use in Pregnancy

  • Category C: Use only if the potential benefit outweighs the risk to the foetus. Prochlorperazine is sometimes used for hyperemesis gravidarum under medical supervision.

13. Use in Elderly

  • Use with caution due to an increased risk of sedation, hypotension, and extrapyramidal symptoms. Start at the lowest effective dose.

14. Use in Kidney Disease

  • No dose adjustment required, but use cautiously as elderly patients or those with renal impairment may be more susceptible to side effects.

15. Use in Liver Disease

  • Use cautiously, as hepatic impairment may reduce drug metabolism. Monitor closely for side effects.

16. Patient Counselling Points

  • Take the medication exactly as prescribed. Avoid activities requiring alertness (e.g., driving) if you feel drowsy.
  • Avoid alcohol or other sedatives while taking prochlorperazine.
  • Inform your doctor immediately if you experience muscle stiffness, tremors, or involuntary movements.
  • Buccal tablets should be placed in the mouth and allowed to dissolve; do not swallow whole.
  • If using for nausea, take at the first sign of symptoms for the best effect.

17. Table of Brand Names, Manufacturer, and Prices in USD

Brand NameManufacturerStrength/Dosage FormPrice (USD)
StemetilSanofi5 mg Tablet$15 (30 tablets)
CompazineGlaxoSmithKline10 mg Tablet$20 (30 tablets)
BuccastemAlliance Pharma3 mg Buccal Tablet$25 (30 tablets)
Generic ProchlorperazineVarious5 mg Tablet$10 (30 tablets)

18. 15 FAQs (Frequently Asked Questions)

1. What is Prochlorperazine used for?
Prochlorperazine is used to treat nausea, vomiting, vertigo, and sometimes acute psychosis or anxiety.

2. How does Prochlorperazine work?
It blocks dopamine receptors in the brain, reducing nausea and vomiting.

3. What is the usual dose for nausea and vomiting?
The usual adult dose is 5–10 mg 2–3 times daily.

4. Can Prochlorperazine cause drowsiness?
Yes, drowsiness is a common side effect.

5. Is Prochlorperazine safe for children?
Yes, for children over 10 kg or >2 years, but doses should be carefully calculated.

6. Can I drink alcohol while taking Prochlorperazine?
No, alcohol can increase sedation and dizziness.

7. Can Prochlorperazine cause muscle stiffness?
Yes, extrapyramidal symptoms, including muscle stiffness, are possible side effects.

8. How should Buccal Prochlorperazine tablets be taken?
Place them between your gum and cheek and let them dissolve.

9. Can Prochlorperazine be used in pregnancy?
Yes, but only if the benefits outweigh the risks, particularly for hyperemesis gravidarum.

10. Does Prochlorperazine interact with other medications?
Yes, it interacts with CNS depressants, anticholinergics, and levodopa.

11. How quickly does Prochlorperazine work?
Relief from nausea or vomiting typically occurs within 30–60 minutes.

12. Can Prochlorperazine cause weight gain?
Weight gain is less common but may occur with prolonged use.

13. What should I do if I miss a dose?
Take it as soon as you remember, but skip it if it’s close to the next dose.

14. Can Prochlorperazine be used long-term?
Long-term use is not recommended due to the risk of tardive dyskinesia and other side effects.

15. How should Prochlorperazine be stored?
Store at room temperature, away from moisture and heat.