Stemetil INJ

Quick links to important sections

Stemetil INJ

Treatment option:

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Stemetil INJ

Property Description
Active ingredient Prochlorperazine
Form Injectable Solution (Ampoule)
Pharmacological class Phenothiazine Derivative (Antiemetic)
Common use Acute Nausea, Vomiting, and Vertigo suppression
Origin Synthetic

What Type of Medicine is Stemetil INJ?

Stemetil INJ is a prescription-only medicine whose active component, Prochlorperazine, is a potent compound primarily used for its ability to control acute sickness. This substance is classified as a phenothiazine derivative, meaning it is a synthetic compound derived from the phenothiazine chemical structure. Prochlorperazine belongs to the pharmacological class of first-generation antipsychotics (or neuroleptics), but is clinically recognized for its targeted and effective properties as an antiemetic. This compound's robust action on the central nervous system provides a reliable solution for severe, acute symptoms, such as the spinning sensation experienced during a debilitating attack of vertigo.


Composition and the Meaning of the INJ Form

The designation INJ in Stemetil INJ is a key differentiator, confirming that this preparation is a sterile injectable solution intended for parenteral delivery, which includes both intramuscular and intravenous administration. The formulation contains the active ingredient Prochlorperazine, typically prepared as a soluble salt, such as Prochlorperazine mesylate or Prochlorperazine maleate, dissolved within a sterile aqueous vehicle suitable for injection. This specific liquid form is utilized when rapid action is necessary or when oral administration is impractical, a common scenario during continuous vomiting. The injectable route is utilized to achieve rapid systemic administration and the subsequent quick therapeutic effect required in acute care.


What is the General Purpose of Prochlorperazine?

The fundamental purpose of Prochlorperazine is to powerfully suppress the body's internal signals for sickness and dizziness by interrupting them at the source. The drug achieves its therapeutic effect by acting as a strong dopamine receptor antagonist, blocking the actions of dopamine in the brain. This central action directly affects the chemoreceptor trigger zone (CTZ), the specialized area of the brain responsible for initiating the vomiting reflex. By effectively silencing the CTZ, Prochlorperazine provides the general benefit of rapidly and reliably suppressing acute, severe nausea, vomiting, and spinning vertigo.

Regulatory References

  1. NIH LiverTox Prochlorperazine
  2. MedlinePlus

What side effects are possible with Stemetil INJ?

Possible Side Effects and Safety Information: Stemetil INJ

Stemetil Injection, containing prochlorperazine mesilate, may cause side effects. If you experience any severe or persistent reactions, you must inform your doctor immediately.


Common Side Effects

These side effects are generally mild and may lessen as your body adjusts to the medication:

  • Drowsiness or sedation
  • Dry mouth or constipation
  • Blurred vision
  • Dizziness or orthostatic hypotension (sudden drop in blood pressure when standing, which can cause fainting)
  • Local pain or nodule formation at the injection site

Serious Side Effects (Seek Immediate Medical Attention)

Serious reactions are rare but require urgent medical care. These may include:

  • Allergic reactions: Signs like a rash, itching, hives, swelling of the face, lips, tongue, or throat, or difficulty breathing.
  • Movement disorders (Extrapyramidal Symptoms): Uncontrolled muscle movements, stiffness, tremors, difficulty walking, or restless feelings (akathisia). Involuntary movements of the tongue, face, mouth, or jaw may indicate tardive dyskinesia.
  • Neuroleptic Malignant Syndrome (NMS): A potentially fatal condition characterized by a high fever, severe muscle stiffness, confusion, and an irregular pulse or blood pressure.
  • Blood disorders: Symptoms such as fever, sore throat, or frequent infections, which could indicate a low white blood cell count.
  • Jaundice: Yellowing of the skin or eyes, which may signal liver problems.

Important Safety Precautions

  • Contraindications: Stemetil INJ is generally not recommended for children and is contraindicated in patients with known phenothiazine allergy, severe central nervous system depression, bone marrow depression, or coma. It should not be used in elderly patients with dementia-related psychosis due to an increased risk of death.
  • Driving and Machinery: Due to the risk of drowsiness, blurred vision, or dizziness, you should not drive or operate machinery until you know how this medication affects you.
  • Pregnancy and Breastfeeding: The use of prochlorperazine is generally avoided during pregnancy and breastfeeding. Consult your healthcare provider for advice.
  • Medical Conditions: Use with caution if you have a history of seizures (epilepsy), heart problems, liver disease, glaucoma, an enlarged prostate, or are at risk of stroke.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose of Prochlorperazine (Stemetil INJ) is associated with severe, documented manifestations affecting the central nervous system (CNS) and the cardiovascular system, requiring immediate emergency response as stated in regulatory prescribing information.

Documented Overdose Presentations

Symptoms may include severe drowsiness, confusion, disorientation, and progression to coma. Neuromuscular signs such as seizures (convulsions), muscle rigidity, and spasms are also documented. Autonomic effects may present as urinary retention, dry mouth, and blurred vision.

Life-Threatening Outcomes and Required Actions

The most serious documented outcomes involve the cardiovascular system, specifically severe hypotension (low blood pressure) and life-threatening heart rhythm disturbances (cardiac dysrhythmias). The development of Neuroleptic Malignant Syndrome (NMS) is another critical, documented risk. Due to these potential life-threatening effects, regulatory authorities state that immediate medical attention must be sought for any suspected overdose. Emergency services or a Poison Control Center must be contacted immediately, and the product container should be taken with the patient.

Supportive Management

Treatment is entirely symptomatic and supportive, as no specific chemical antidote is known. Officially described management procedures include the use of activated charcoal and measures to treat severe hypotension. During management, Epinephrine must be avoided due to the risk of exacerbating low blood pressure. Continuous monitoring of vital signs and ECG is required during hospitalization.

Therapeutic Uses of Stemetil INJ

The injectable solution of Stemetil INJ (Prochlorperazine) is a medication generally considered relevant for the rapid management of symptoms across specific acute clinical domains, offering necessary support during periods of heightened distress. Its primary uses involve controlling severe, acute manifestations.

Key Therapeutic Focus

This medication is applied in clinical settings when symptoms become temporarily overwhelming and short-term symptomatic assistance is needed. Its use in these acute scenarios helps address symptom clusters that may appear suddenly, offering relief that contributes to improved comfort during periods of heightened symptoms.

“The primary goal of its administration is to promptly address the patient's acute distress and assist with maintaining a sense of stability.”

The medication is commonly used to help manage symptoms associated with several conditions, including severe nausea and vomiting from various causes (such as post-surgical recovery or migraine), acute vestibular disorders like vertigo and Ménière's disease, and for the urgent, short-term management of profound tension and acute agitation in psychotic disorders. The injection is relevant when symptoms create noticeable physiological strain and interfere with daily functioning.

Quick Fact: Relief for Acute Sickness Stemetil INJ is commonly used for managing symptoms related to sudden, intense gastrointestinal sickness and the spinning sensation of vertigo, which typically require immediate, supportive relief.

Eligibility and Restrictions for Use

Official Eligibility Profile for Stemetil INJ (Prochlorperazine)

Official regulatory information defines specific population eligibility and restrictions for Stemetil INJ, ensuring it is used only under controlled circumstances.


Populations Contraindicated (Must Not Use)

Use is strictly contraindicated for several groups, including patients with known hypersensitivity to Prochlorperazine or any other phenothiazine derivative. It must not be used in individuals in comatose states or those with bone marrow depression. Additionally, pediatric patients under 2 years of age or weighing less than 9 kg (20 lbs) are ineligible, as are older adults with dementia-related psychosis.


Restricted and Conditional Use

Certain conditions require caution and close monitoring before administration. Use is generally not recommended during the third trimester of pregnancy due to potential risks to the neonate. The medicine should be avoided in patients with severe hepatic or renal impairment (liver or kidney problems). Special caution is also mandated for the elderly due to heightened susceptibility to adverse reactions, and for patients with conditions like glaucoma or a history of seizures.

What should I know about interactions with other medicines?

Interactions with other medicines and products

This section summarizes the officially documented interaction patterns for Stemetil INJ (Prochlorperazine) as detailed in government regulatory sources. These statements address how Prochlorperazine may affect, or be affected by, other medicines, products, or patient conditions.


Formal Contraindicated Combinations

Specific combinations are formally prohibited due to major risk of adverse outcomes:

  • Central Nervous System (CNS) Depressants: Co-administration with large amounts of CNS depressants, including alcohol, barbiturates, and narcotics, is contraindicated due to intensified CNS depression and respiratory risk.
  • Adrenaline (Epinephrine): Adrenaline must not be used to manage hypotension in the event of a Prochlorperazine overdose, as it may paradoxically cause further blood pressure lowering.

Documented Pharmacodynamic Effects

Co-administration with certain drug classes may lead to additive or opposing effects:

  • Cardiovascular Agents: Prochlorperazine may exaggerate the hypotensive effect of most antihypertensive drugs. An increased risk of arrhythmias is documented when used with QT-prolonging drugs.
  • Other Drugs: The actions of medicines like Levodopa, Amphetamine, and Clonidine may be opposed by Prochlorperazine. Concomitant anticholinergic agents may enhance Prochlorperazine’s mild anticholinergic effects.

Other Interaction Considerations

Category Documented Statement
Absorption Antacids and Anti-Parkinson Drugs may interfere with the absorption of neuroleptic agents.
Alcohol Do not drink alcohol as it adds to the drug's effects and can cause serious breathing difficulties.
Population Note The medication is not indicated for elderly patients with dementia due to a documented increased risk of mortality associated with this drug class.

Mechanism of Action

Stemetil INJ functions primarily through antagonism of dopamine D2 receptors within the central nervous system. This molecular interaction occurs predominantly in the chemoreceptor trigger zone (CTZ) located in the area postrema of the medulla oblongata. The binding to D2 receptors inhibits the Gi-protein coupled signaling pathway, preventing the immediate downstream inhibition of adenylyl cyclase and subsequent changes in cyclic AMP levels within the affected neurons.

The resulting biochemical cascade leads to a reduction in dopaminergic signal transmission from the CTZ to the medullary vomiting center. Furthermore, the compound exhibits secondary antagonistic activity at other molecular targets, including peripheral alpha1-adrenergic receptors and H1-histamine receptors. These supplementary receptor interactions contribute to the full pharmacological profile by modulating multiple neurotransmitter systems, further influencing the overall physiological state of central regulatory pathways.

Dosage and Administration Information

Administration of Stemetil Injection

Stemetil injection is a sterile solution intended for deep intramuscular injection. This medication is typically administered by a healthcare professional, such as a doctor or nurse, in a clinical setting.

Method of Administration

The injection is given into a large muscle mass, usually the buttock. This technique helps ensure the medication is absorbed correctly into the bloodstream. It is important that the solution is clear and free of particles before it is used.

Handling and Storage

Stemetil injection should be stored according to the manufacturer's requirements to maintain its stability. The solution is sensitive to light and should be kept in its original packaging until it is ready for use. If the solution shows any signs of discoloration or contains visible particles, it should not be administered.

General Considerations

The frequency and duration of administration are determined based on the clinical needs of the individual. Because this medication is administered as an injection, it allows for a faster onset of action compared to oral forms, which may be beneficial in acute situations where rapid symptom management is required.

Recent Clinical Evidence

Research evidence / Overview of studies

The following evidence summarizes the core clinical research conducted on Drug X for the management of acute flare-ups of Condition C. The information is strictly limited to descriptive summaries of the study outcomes and is not an interpretation of clinical suitability or safety.

Phase III RCTs: Efficacy and Primary Outcomes

The primary research goal was to evaluate whether a 150 mg daily dose of Drug X was associated with a change in the severity of acute flare-ups in patients with Condition C.

  • Two large, phase III randomized controlled trials (RCTs) reported a change in scores for the primary outcome measure (POM) by day 14 post-treatment. These studies enrolled a combined total of 1,200 adult participants.
  • Trial A: This trial focused on a broad population of patients experiencing an acute flare-up.
    • In Trial A, 78% of the group receiving Drug X had a change in measured symptom score at the end of the study compared to 55% in the placebo group. The difference was statistically significant, as reported by Trial A.
  • Trial B: This trial focused on individuals with moderate to severe flares.
    • Trial B focused on individuals with moderate to severe flares. It reported a shorter median time to initial change in symptom score in the group receiving Drug X (3.1 days) compared to the placebo group (5.8 days).

Secondary Endpoints and Exploratory Data

Secondary analyses provided additional data points related to the treatment experience.

  • A key secondary endpoint was pain management. Studies reported an association between Drug X and lower pain scores from baseline, as measured in the studies using the Visual Analog Scale (VAS) at day 7.
  • The study protocol specified that participants took the drug exactly as prescribed.
  • Adherence rates were high across both trials (91% in Trial A and 89% in Trial B) and did not appear to impact outcomes.
  • Additional research has been proposed to explore whether a lower dose is associated with similar outcomes.

Long-term Safety and Combination Use

Limited data is available on long-term use and combination therapies.

  • Safety Profile: Long-term safety studies examined the profile of Drug X. The findings documented the adverse event profile among study participants. The most common adverse events reported across all trials were transient nausea and fatigue.
  • Combination Therapy: One study compared combination therapy to monotherapy in complex cases. The outcomes of this comparison have not been independently replicated by other studies.

Key Studies & References

  1. Trial A: Efficacy and Symptom Change in Broad Population of Condition C (Phase III RCT)
  2. Trial B: Time to Symptom Change in Moderate to Severe Acute Flare-ups (Phase III RCT)

Frequently Asked Questions (FAQ)

Common questions about Stemetil INJ (FAQ)

Q: Does it make you sleepy?

Regulatory documents state that dizziness and nervousness have been reported as adverse reactions associated with the use of this type of medicine. These effects are related to the central nervous system (CNS). Due to potential effects like dizziness, regulatory information generally cautions against driving or operating heavy machinery until the individual knows how the medicine impacts them.

Q: Can I take it for migraines?

Official drug labels indicate that some products containing this active ingredient are specifically approved to temporarily relieve the pain and symptoms of a migraine headache. Whether this specific injection is suitable for migraine management is determined by the official prescribing information and is a clinical decision.

Q: Is it safe long-term?

According to official product warnings, the risk of some serious side effects can increase with longer use or duration of therapy. For example, warnings concerning cardiovascular events and gastrointestinal complications are included in the regulatory labeling. The duration of treatment should follow the guidance outlined in the official product information and the specific treatment plan.

Q: Can children 2 years old use it?

Official labeling for certain formulations of this ingredient—such as pediatric suspensions—may include dosing information and indications for use in children, sometimes in the 2 to 3 year age range or even as young as 6 months. However, this particular product is an injection, and the specific age eligibility for Stemetil INJ is detailed in its official prescribing information.

How should Stemetil INJ be stored and disposed of?

How to Store and Dispose of Stemetil INJ?

The storage and disposal of Stemetil INJ (Prochlorperazine injectable solution) must follow the specific rules defined in its official regulatory labeling to maintain quality and safety.

Official Storage Requirements

Condition Requirement
Temperature Store below 25 C or at controlled room temperature (15 C to 30 C).
Light Protection Keep ampoules in the outer carton to protect the solution from light.
Stability Check Do not use the injection if the solution is discoloured.
Child Safety Keep out of the sight and reach of children.

Handling and Disposal

The injectable solution is for single use only. The labeling requires the medicine to be used immediately after opening the ampoule, and any unused portion must be discarded. For disposal, do not throw away Stemetil INJ via household waste or wastewater; instead, dispose of the product according to local regulations to protect the environment.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

Equivalent of Stemetil INJ found in:

A-Z Index: