Metocal Ampoule
A comprehensive guide to the use of Metocal injections for treating nausea and vomiting, with important warnings and side effects.
Quick Facts
Definition and Uses
Metocal injection is a fast-acting treatment containing the active ingredient metoclopramide, which belongs to a class of drugs known as dopamine antagonists. This medication works primarily by speeding up the movement of food through the stomach and intestines, in addition to its effect on an area in the brain responsible for the sensation of nausea. This dual effect makes it effective in treating and preventing severe vomiting and nausea.
- Treatment of Acute Nausea and Vomiting: This is its main use, especially when the patient is unable to take medication orally.
- Post-Surgery: Used to prevent nausea and vomiting that may occur after anesthesia.
- During Chemotherapy: Given to prevent severe nausea associated with some types of cancer chemotherapy.
Metocal is an effective treatment for symptoms, but it does not treat the underlying cause of the problem. Therefore, it should be used based on a precise medical diagnosis and only for the period specified by the doctor.
How to Use and Dosage
Metocal injections are administered by intramuscular injection or slowly into a vein by healthcare professionals. It is crucial to adhere to the prescribed dose strictly to avoid the risk of side effects, especially involuntary movements.
- For Adults: One injection (one ampoule) as needed, up to a maximum of 4 times a day.
- For Children: Half an injection (half an ampoule) as needed, up to a maximum of 3 times a day.
- Important Instructions: You must wait at least 6 hours between each dose to avoid accumulation of the drug in the body and to reduce the risk of neurological side effects.
The prescribed dose should not be exceeded, especially in children and adolescents, as they are more susceptible to developing involuntary muscle movements as a side effect of the drug.
Side Effects
Like all medicines, Metocal injections may cause side effects. It is important to be aware of potential symptoms, especially those that require stopping treatment and contacting a doctor immediately.
- Common Symptoms: Feeling drowsy, fatigued, and dizzy.
- Gastrointestinal Symptoms: May cause diarrhea or abdominal bloating.
- Involuntary Movements (Serious): Spasms and abnormal movements in the head, neck, and face may occur. Treatment must be stopped immediately if this happens.
- Neuroleptic Malignant Syndrome (Rare and Serious): Symptoms include fever, muscle rigidity, and altered consciousness. This condition requires emergency attention.
- Cardiac Effects: Especially with intravenous injection, it may cause a drop in blood pressure or a slow heart rate.
If any worrying or severe symptoms appear, especially involuntary movements, you should stop receiving treatment and contact your doctor immediately.
Warnings and Precautions
There are some conditions where the use of Metocal injections is strictly prohibited. It is essential to inform your doctor of your complete medical history before receiving treatment.
- Absolute Contraindications: Allergy to metoclopramide, gastrointestinal bleeding, obstruction, or perforation, pheochromocytoma, or a history of drug-induced involuntary movements.
- Drug Interactions: Should not be used with Parkinson’s disease medications like levodopa, as their effects are antagonistic.
- Epilepsy: Should be used with caution in patients with epilepsy, as it may increase the risk of seizures.
- Kidney and Liver Diseases: The dose may need to be adjusted for patients with impaired kidney or liver function.
Due to its drowsy effect, you should avoid driving or operating heavy machinery after receiving the injection until you know how the drug affects you.
Frequently Asked Questions (FAQ)
How do Metocal injections work to stop vomiting quickly?
Metocal injections work through a rapid, dual mechanism. First, they directly affect the digestive system by increasing the speed of stomach contractions, which pushes its contents into the intestines and prevents reflux. Second, and more importantly, they act on the brain by blocking the effect of dopamine in the “vomiting center,” the area responsible for triggering the sensation of nausea.
When the drug is administered by injection, it enters the bloodstream directly and begins to work very quickly, often within a few minutes. This rapid action makes it an ideal choice in cases of severe vomiting or when the patient is unable to keep oral medications down, such as after surgery or during chemotherapy.
What are the “involuntary movements” that the injections can cause?
Involuntary movements, or “extrapyramidal reactions,” are one of the most serious potential side effects of Metocal injections. They can manifest as sudden muscle spasms, especially in the muscles of the face, neck, and jaw. The patient may have difficulty speaking or swallowing, or experience abnormal eye movements or neck stiffness.
These symptoms are more common in children and young adults and can occur even after just one dose. With long-term use, another type of involuntary movement called “tardive dyskinesia” may develop, which can be permanent. Therefore, treatment should be stopped immediately and a doctor notified if any abnormal movement appears.
Why is it necessary to wait at least 6 hours between injections?
Adhering to a minimum 6-hour interval between doses is a crucial safety measure. The primary reason is to prevent the drug from accumulating to high levels in the body, which significantly increases the risk of serious side effects, especially dangerous involuntary muscle movements. The body needs sufficient time to process and eliminate the dose before receiving the next one.
Even if vomiting continues after receiving an injection, another dose should never be given before 6 hours have passed. Taking doses too close together is equivalent to an overdose and increases the likelihood of acute neurological reactions. This rule ensures the safe use of the drug and minimizes potential risks.
Can I drive after receiving a Metocal injection?
It is strongly advised to avoid driving or operating heavy machinery after receiving a Metocal injection. One of the most common side effects of this drug is causing drowsiness, dizziness, and fatigue. These symptoms can significantly impair your concentration and reaction time, making driving unsafe.
The sedative effect varies from person to person and can be severe in some. You should wait to see how the drug affects you before considering driving. If you feel any degree of drowsiness or lack of focus, you must avoid driving completely to protect yourself and others on the road.
Are these injections safe for children?
Metocal injections must be used with extreme caution in children and adolescents. This age group is more sensitive and susceptible to the risk of developing neurological side effects, especially acute involuntary muscle movements (dystonic reactions). This risk is the main reason why adherence to the precise dosage and the time interval between doses is of utmost importance.
This medication should never be given to children without a prescription and supervision from a doctor. The doctor calculates the appropriate dose based on the child’s weight and age, and parents must monitor the child carefully for any signs of muscle spasms or abnormal movements and report them to the doctor immediately if they appear.
Why are Metocal injections not used in cases of intestinal bleeding?
Metocal is contraindicated in situations where stimulating gastrointestinal motility could be dangerous, such as in the presence of bleeding, obstruction, or perforation in the stomach or intestines. The drug works by increasing the force and speed of muscle contractions in the stomach and intestinal walls to push food forward.
If there is bleeding or a perforation, these strong contractions could significantly worsen the condition, increasing the severity of the bleeding or enlarging the perforation. In the case of an obstruction, trying to push contents against a blockage can cause severe pain and increase the risk of rupture. Therefore, using the drug in these situations is dangerous and prohibited.
Can I receive the injection if I am using medication for Parkinson’s disease?
No, you should never receive a Metocal injection if you are using medications to treat Parkinson’s disease, especially drugs containing levodopa. The reason is that the mechanisms of action of these two types of drugs are completely opposite. Parkinson’s disease is caused by a lack of dopamine in the brain, and drugs like levodopa work to increase dopamine levels.
On the other hand, Metocal acts as a “dopamine antagonist,” meaning it blocks the effect of dopamine in the body. Taking both drugs together will lead to them canceling each other’s effects. Metocal will reduce the effectiveness of the Parkinson’s medication, and the Parkinson’s medication may reduce the effectiveness of Metocal. Therefore, this concurrent use is contraindicated.
What is “Neuroleptic Malignant Syndrome”?
Neuroleptic Malignant Syndrome (NMS) is a very rare but serious and life-threatening reaction to drugs that block the effect of dopamine, like Metocal. It is a medical emergency that requires immediate hospital treatment. It is very important to know its warning signs to be able to act quickly if it occurs.
The main symptoms of this syndrome include a very high body temperature (fever) without an infection, severe muscle rigidity, confusion or altered mental state, pale skin, and profuse sweating. If a patient experiences these symptoms together, treatment should be stopped immediately, and they should be taken to the nearest emergency department.
Do Metocal injections cause diarrhea?
Yes, diarrhea is a potential side effect of Metocal injections. This happens because the drug’s main mechanism of action is to increase and accelerate the movement of the intestines. While this effect is beneficial for emptying the stomach and relieving nausea, it can sometimes be excessive, causing food to pass through the intestines too quickly.
This rapid transit reduces the time available for the intestines to absorb water from the stool, making it watery and causing diarrhea. This side effect is usually mild and temporary. However, if the diarrhea is severe or persistent, it is important to speak with your doctor.
Can Metocal injections be used for long periods?
In general, it is recommended to use Metocal injections for the shortest possible duration (usually not exceeding 5 days). Long-term use (more than 3 months) is generally not recommended due to the increased risk of a serious side effect called “Tardive Dyskinesia.” This condition causes repetitive, involuntary movements, often in the face and mouth, and can be permanent even after stopping the drug.
The risk is higher in the elderly, especially women. Certain chronic medical conditions, such as severe gastroparesis, may require longer treatment, but this must be done under strict medical supervision with continuous monitoring for any early signs of these involuntary movements.
Disclaimer and Information Sources
- Content Purpose: The information in this guide is for awareness and educational purposes only and is not a substitute for professional medical advice. Do not use this or any other medication without consulting your doctor or pharmacist.
- Source of Information: This content was prepared based on official, documented medical sources appropriate for the topic (such as official drug leaflets, health ministry guidelines, FDA directives, or specialized medical organizations).
- Publication Date | Last Updated: 21-09-2025
Dr. Ahmad Baker, PharmD
Senior Pharmacist & Health Educator
With over 23 years of clinical experience in hospital and community pharmacy across Egypt and Saudi Arabia, Dr. Ahmad specializes in reproductive health and pharmaceutical safety. He is dedicated to providing evidence-based guidance to empower patients in the MENA region.
Medical Disclaimer: This content is for educational purposes and reflects the latest pharmaceutical protocols. It is not a substitute for personal medical advice. Always consult Dr. Ahmad Baker or your healthcare provider before starting any treatment.