Stemetil's Active Ingredient: Prochlorperazine
Stemetil is the brand name for the active drug prochlorperazine maleate, which belongs to a class of medications called phenothiazine antipsychotics. The drug works by blocking the effects of a natural chemical called dopamine in certain areas of the brain. By modulating these neurotransmitters, prochlorperazine provides a range of therapeutic effects, primarily targeting the central nervous system.
Key Uses of Stemetil Tablet
Nausea and Vomiting
One of the most common applications for Stemetil is to control and prevent severe nausea and vomiting from various causes. This makes it particularly useful for:
- Chemotherapy and radiation therapy: Managing the severe side effects of cancer treatments.
- Post-operative recovery: Alleviating sickness after surgery where general anesthesia was used.
- Migraine-related sickness: Controlling the severe nausea and vomiting that often accompanies migraine headaches.
The drug works by blocking dopamine receptors in the chemoreceptor trigger zone (CTZ), a part of the brain that signals the vomiting center.
Vertigo and Dizziness
Stemetil is a potent vestibular suppressant, meaning it effectively treats vertigo—the sensation of spinning or dizziness—which can arise from inner ear problems. Conditions for which Stemetil may be prescribed include:
- Ménière's disease: An inner ear disorder causing vertigo, hearing loss, and tinnitus.
- Labyrinthitis: Inflammation of the inner ear that can lead to dizziness and balance issues.
For these conditions, Stemetil suppresses the abnormal signals coming from the balance organs, providing symptomatic relief during acute attacks.
Psychotic Disorders
As a phenothiazine antipsychotic, Stemetil is also used in the management of specific mental health conditions, including:
- Schizophrenia: Particularly in the chronic stage, to help manage symptoms like agitation, confusion, and hostility.
- Acute mania: For the short-term control of severe over-active behavior or thoughts.
It is important to note that for these uses, Stemetil should be taken under strict medical supervision and its role is often as an adjunct to other therapies.
Short-term Anxiety
In some cases, Stemetil can be used for the short-term management of generalized non-psychotic anxiety, particularly when other anti-anxiety medications have been ineffective. Due to its side effect profile, its use for anxiety is generally limited to a short duration and specific doses.
Stemetil (Prochlorperazine) vs. Other Common Antiemetics
| Feature | Stemetil (Prochlorperazine) | Promethazine (Phenergan) | Metoclopramide (Reglan) |
|---|---|---|---|
| Drug Class | Phenothiazine Antipsychotic | First-generation Antihistamine | Dopamine Antagonist |
| Mechanism | Blocks dopamine (D2) receptors in the chemoreceptor trigger zone | Blocks H1 histamine receptors and has anticholinergic effects | Blocks dopamine (D2) receptors peripherally and centrally |
| Key Indications | Severe nausea, vomiting, vertigo, schizophrenia, anxiety | Nausea, vomiting, motion sickness, allergy symptoms | Nausea, vomiting, gastroparesis (delayed stomach emptying) |
| Effectiveness | Shown to be more effective than promethazine for nausea relief in studies | Effective but potentially less powerful than prochlorperazine for nausea | Mixed reviews on effectiveness for nausea, with many reporting negative effects |
| Sedation | Can cause drowsiness, though generally less sedating than chlorpromazine | Known for significant sedative effects | May cause drowsiness |
| Serious Risks | Tardive dyskinesia, NMS, higher mortality in dementia | Respiratory depression, especially in young children | Tardive dyskinesia, particularly with long-term use |
Important Considerations and Side Effects
Like all potent medications, Stemetil can cause a range of side effects. While many are mild and temporary, some can be severe and require immediate medical attention.
Common side effects include:
- Drowsiness, dizziness, and unsteadiness
- Dry mouth and constipation
- Blurred vision
- Restlessness and agitation
Serious or less common side effects include:
- Extrapyramidal Symptoms (EPS): Involuntary movements, tremors, muscle stiffness, or difficulty with motor control. This is more common with higher doses and prolonged use.
- Tardive Dyskinesia: A potentially irreversible condition involving uncontrollable, rhythmic movements of the face, mouth, or jaw. The risk is higher with long-term use, especially in elderly women.
- Neuroleptic Malignant Syndrome (NMS): A rare but potentially fatal condition characterized by high fever, severe muscle rigidity, altered mental status, and autonomic instability.
Precautions and Contraindications
Stemetil should not be used in certain patients and situations. Key contraindications and precautions include:
- Dementia-related psychosis: Use in elderly patients with this condition is associated with an increased risk of death and is not approved.
- Severe CNS depression: Avoid use in comatose patients or those under the influence of large amounts of CNS depressants like alcohol or narcotics.
- Children: Not recommended for children under two years of age or weighing less than 10 kg.
- Liver or Kidney Disease: Use with caution, as dosage adjustments may be necessary.
- Heart problems: Use with caution in patients with a history of cardiovascular disorders.
- Parkinson's disease: May cause pseudo-parkinsonian symptoms and should be used with caution.
Patients should also avoid alcohol while taking Stemetil, as it can worsen side effects like drowsiness. It is also essential to use sun protection, as the medication can increase photosensitivity.
Conclusion
Stemetil is a powerful and effective medication primarily used to control severe nausea, vomiting, and vertigo. Its uses extend to managing certain mental health conditions, like schizophrenia and short-term anxiety, under specific circumstances. As a first-generation antipsychotic, it carries a risk of significant side effects, including extrapyramidal symptoms and the potentially irreversible tardive dyskinesia with long-term use. As a prescription medication, Stemetil must always be taken exactly as directed by a healthcare professional, who can weigh the potential benefits against the risks for each individual patient. If you have any concerns or questions about Stemetil, consult your doctor or pharmacist. An excellent resource for more information is the NHS Prochlorperazine guide.
