Understanding Stemetil (Prochlorperazine)
Stemetil, whose generic name is prochlorperazine, is a phenothiazine medication that works by blocking a chemical in the brain [1.11.1]. It is prescribed for various conditions, including the treatment of balance problems like vertigo (from causes such as Meniere's Syndrome or labyrinthitis), and to control severe nausea and vomiting from any cause, including migraines [1.11.1]. Additionally, it can be used in the management of schizophrenia, mania, and for the short-term treatment of anxiety [1.4.3, 1.11.1]. Despite its benefits, prochlorperazine is not a first-choice medication for some conditions due to a risk of serious side effects, such as extreme drowsiness and uncontrolled muscle movements [1.4.1]. The brand name Compazine has been discontinued in the U.S., but generic versions are available [1.3.4].
Absolute Contraindications: Who Should Never Take Stemetil?
Certain individuals should not take Stemetil under any circumstances due to the high risk of severe adverse reactions. These are known as absolute contraindications.
- Allergy: Individuals with a known hypersensitivity or allergy to prochlorperazine or any other phenothiazine medications (like chlorpromazine) should not take it. Signs of an allergic reaction can include rash, hives, difficulty breathing or swallowing, and swelling of the face, lips, tongue, or throat [1.2.2, 1.11.1].
- Children Under 2: Prochlorperazine is not approved for use in children under two years of age or those weighing less than 20 pounds (9 kg) [1.3.1, 1.3.5]. Side effects are high in children, and alternatives are often considered for those over two as well [1.2.1].
- Comatose or Depressed CNS States: It should not be used by people who are in a coma, have a decreased level of consciousness, or are experiencing central nervous system (CNS) depression, especially after recent use of large amounts of alcohol, sedatives, tranquilizers, or narcotic medications [1.2.5, 1.3.3, 1.3.1].
- Dementia-Related Psychosis in the Elderly: Stemetil carries an increased risk of death in older adults suffering from dementia-related psychosis and is not approved for this use [1.6.4, 1.4.3]. Most deaths in this group appear to be cardiovascular or infectious in nature [1.6.4].
Populations Requiring Special Precaution
For several groups, Stemetil is not strictly forbidden but requires careful consideration and consultation with a doctor due to heightened risks.
Elderly Patients (65 and over)
Older adults are more sensitive to the side effects of antipsychotics like prochlorperazine [1.6.4]. They are more likely to experience issues such as low blood pressure (hypotension), confusion, constipation, urinary retention, and serious neuromuscular reactions like parkinsonism and tardive dyskinesia [1.6.4]. The risk of falls due to dizziness and motor instability is also a significant concern [1.6.4]. Dose selection for elderly patients should be cautious, typically starting at the lower end of the range [1.6.5].
Children and Adolescents
Use in children requires special care. It is not recommended for children under 2 years old or weighing under 20 pounds [1.3.5]. Side effects such as sedation and extrapyramidal symptoms (uncontrolled muscle movements) are common in pediatric patients [1.2.1]. The medication should be avoided in children and adolescents whose symptoms might suggest Reye's syndrome, as Stemetil can mask the signs of this serious condition [1.6.4].
Pregnancy and Breastfeeding
- Pregnancy: The safety of prochlorperazine during pregnancy has not been definitively established [1.7.1]. Taking antipsychotic medication during the third trimester may lead to withdrawal symptoms or movement disorders in the newborn, such as agitation, breathing problems, and feeding difficulties [1.7.1, 1.4.4]. However, some guidelines state it can be used if the potential benefits for treating severe and intractable nausea and vomiting are judged to outweigh the possible risks [1.7.1, 1.7.3].
- Breastfeeding: Prochlorperazine is known to be excreted in breast milk, though likely in small amounts [1.7.3, 1.7.4]. While it can generally be used if the baby is healthy, it's recommended for occasional or short-term use. Mothers should monitor their infants for any unusual sleepiness, irritability, or poor feeding [1.7.3].
Pre-existing Medical Conditions
Individuals with certain health problems must tell their doctor before taking Stemetil, as it can worsen their condition or cause severe side effects.
- Cardiovascular Issues: Patients with heart disease, a history of irregular heartbeat, heart failure, or severe cardiac reserve deficiency should use Stemetil with caution [1.2.2, 1.9.1]. It can cause hypotension (low blood pressure) and EKG changes [1.9.1, 1.2.5]. In rare cases, sudden death possibly caused by heart problems has been reported [1.11.4].
- Liver or Kidney Disease: Those with hepatic or renal impairment should exercise caution [1.2.3]. Prochlorperazine can cause liver damage, and signs like jaundice (yellowing skin/eyes) require immediate medical attention [1.8.1, 1.11.1].
- Parkinson's Disease: Stemetil is contraindicated as it can worsen the motor symptoms of Parkinson's disease [1.10.1, 1.11.1]. It works by blocking dopamine, the chemical deficient in Parkinson's patients [1.10.2].
- Seizure Disorders (Epilepsy): Prochlorperazine can lower the seizure threshold, making seizures more likely. Patients with a history of epilepsy need to use it with caution, and their anticonvulsant medication doses may need adjustment [1.2.1, 1.2.5].
- Glaucoma: The drug is not recommended for individuals with narrow-angle glaucoma as it can increase eye pressure [1.2.1, 1.2.2].
- Prostate Problems: Men with an enlarged prostate (prostatic hypertrophy) may experience increased difficulty urinating [1.2.1, 1.2.2].
- Blood Disorders: Patients with a history of blood or bone marrow problems, such as agranulocytosis or leukopenia, should use Stemetil with caution as it can lower white blood cell counts, increasing infection risk [1.3.5, 1.11.1].
- Phaeochromocytoma: People with this rare adrenal gland tumor may experience a severe increase in blood pressure [1.2.2, 1.11.1].
Stemetil Drug Interactions
Combining Stemetil with other substances can lead to dangerous interactions. It's vital to inform your doctor of all medications you take.
- CNS Depressants: The effects of alcohol, sedatives, opioids, and anesthetics are intensified, which can lead to severe drowsiness and respiratory depression [1.5.5, 1.3.1].
- Anticholinergic Drugs: When taken with medications for bladder problems or travel sickness, the risk of side effects like dry mouth, blurred vision, and constipation increases [1.2.1].
- Blood Pressure Medications: Stemetil can interfere with drugs for high blood pressure [1.5.2].
- Dopamine Agonists: Medications for Parkinson's disease like levodopa can have their effects antagonized by Stemetil [1.5.2, 1.10.3].
Comparison Table: Condition vs. Risk Level
| Condition | Risk Level with Stemetil | Rationale |
|---|---|---|
| Allergy to Phenothiazines | High / Contraindicated | Risk of severe, life-threatening allergic reaction [1.11.1]. |
| Children < 2 years old | High / Contraindicated | Not approved for this age group due to high risk of adverse effects [1.3.1]. |
| Elderly with Dementia | High / Contraindicated | Increased risk of death from cardiovascular events or infection [1.6.4]. |
| Parkinson's Disease | High / Contraindicated | Worsens motor symptoms by blocking dopamine [1.10.1, 1.10.3]. |
| Liver or Kidney Disease | Moderate to High / Use with Caution | Potential for drug accumulation and hepatotoxicity (liver damage) [1.2.3, 1.8.1]. |
| Heart Disease / Irregular Heartbeat | Moderate to High / Use with Caution | Can cause low blood pressure and abnormal heart rhythms [1.2.2, 1.9.1]. |
| History of Seizures (Epilepsy) | Moderate / Use with Caution | Lowers the seizure threshold, increasing the risk of fits [1.2.1, 1.2.2]. |
| Pregnancy (3rd Trimester) | Moderate / Use with Caution | Risk of withdrawal symptoms and movement disorders in the newborn [1.7.1]. |
Conclusion
While Stemetil (prochlorperazine) is an effective medication for specific conditions, it is not suitable for everyone. A thorough understanding of who shouldn't take Stemetil is critical for patient safety. Absolute contraindications include allergies, very young children, and elderly patients with dementia-related psychosis [1.11.1, 1.3.1, 1.6.4]. Numerous other conditions, particularly those affecting the heart, liver, and nervous system, require significant caution and medical supervision [1.2.2, 1.2.3]. Always disclose your full medical history and all current medications to your healthcare provider to ensure Stemetil is a safe choice for you. Do not drink alcohol while taking this medicine, and be aware of potential side effects like drowsiness that can impair your ability to drive or operate machinery [1.11.1, 1.11.2].
Authoritative Link: For more detailed patient information on prochlorperazine, consult the National Health Service (NHS) website.
