Plasil Ampoule (Injection)
A comprehensive guide on using Plasil injections to treat nausea and vomiting, detailing important warnings and side effects.
Quick Facts
Definition and Uses
Plasil injection is a fast-acting treatment containing the active ingredient Metoclopramide, which belongs to a class of drugs known as dopamine antagonists. This medication primarily works by accelerating the movement of food through the stomach and intestines, in addition to its effect on a brain region responsible for the sensation of nausea. This dual action makes it effective in treating and preventing severe nausea and vomiting.
- 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: Administered to prevent severe nausea associated with certain types of cancer chemotherapy.
Plasil is an effective symptomatic treatment, but it does not treat the underlying cause of the problem. Therefore, it should be used based on an accurate medical diagnosis and only for the period specified by the doctor.
Method of Use and Dosage
Plasil is administered via intramuscular injection or slowly intravenously by healthcare professionals. It is crucial to adhere strictly to the prescribed dosage 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 per day.
- For Children: Half an injection (half ampoule) as needed, up to a maximum of 3 times per day.
- Important Instructions: A minimum interval of 6 hours must be maintained between each dose to prevent drug accumulation in the body and reduce the risk of neurological side effects.
The prescribed dosage should not be exceeded, especially in children and adolescents, as they are more susceptible to developing involuntary muscle movements as a side effect.
Side Effects
Like all medicines, Plasil injection can 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: Drowsiness, fatigue, and dizziness.
- Gastrointestinal Symptoms: May cause diarrhea or abdominal bloating.
- Involuntary Movements (Serious): Spasms and abnormal movements of the head, neck, and face may occur. Treatment must be stopped immediately if they appear.
- Neuroleptic Malignant Syndrome (Rare and Serious): Symptoms include fever, muscle rigidity, and impaired consciousness. This condition requires emergency medical attention.
- Cardiac Effects: Especially with intravenous injection, it may cause a drop in blood pressure or a slow heart rate.
If any concerning or severe symptoms appear, especially involuntary movements, you must stop receiving treatment and contact your doctor immediately.
Warnings and Precautions
There are some conditions where the use of Plasil injection is strictly contraindicated. 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 Disease: A dose adjustment may be necessary 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 medication affects you.
Frequently Asked Questions
How does Plasil injection work to stop vomiting quickly?
Plasil injection works through a rapid, dual mechanism. First, it directly affects the digestive system by increasing the speed of stomach contractions, which pushes its contents into the intestines and prevents reflux. Second, and more importantly, it acts 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 effect makes it an ideal choice for severe vomiting or when the patient cannot keep oral medications down, such as after surgery or during chemotherapy.
What are the “involuntary movements” that the injection can cause?
Involuntary movements, or “extrapyramidal reactions,” are one of the most serious potential side effects of Plasil injection. 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 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 vital for safety. The primary reason is to prevent the drug from accumulating to high levels in the body, which significantly increases the risk of side effects, especially dangerous involuntary muscle movements. The body needs enough time to process and eliminate one dose before receiving the next.
Even if vomiting continues after receiving an injection, another dose should never be taken before 6 hours have passed. Taking doses too close together is considered an overdose and increases the likelihood of acute neurological reactions. This rule ensures the safe use of the medication and minimizes potential risks.
Can I drive a car after receiving a Plasil injection?
It is strongly advised to avoid driving or operating heavy machinery after receiving a Plasil injection. One of the most common side effects of this medication 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.
Is this injection safe for children?
Plasil injection should 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 strict adherence to the exact dosage and time interval between doses is crucial.
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 should carefully monitor the child for any signs of muscle spasms or abnormal movements and report them to the doctor immediately if they appear.
Why is Plasil injection not used in cases of intestinal bleeding?
Plasil is contraindicated in situations where stimulating gastrointestinal motility could be dangerous, such as in the presence of bleeding, obstruction, or perforation of the stomach or intestines. The drug works by increasing the strength 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 can 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 forbidden.
Can I take the injection if I use medications for Parkinson’s disease?
No, you should never take a Plasil 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 dopamine deficiency in the brain, and drugs like Levodopa work to increase dopamine levels.
On the other hand, Plasil acts as a “dopamine antagonist,” meaning it blocks the effect of dopamine in the body. Taking both drugs together will cause them to cancel each other out. Plasil will reduce the effectiveness of the Parkinson’s medication, and the Parkinson’s medication may reduce the effectiveness of Plasil. 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 dopamine’s effects, such as Plasil. It is a medical emergency that requires immediate hospital treatment. It is crucial 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 a change in mental state, pale skin, and heavy sweating. If a patient experiences these symptoms together, treatment should be stopped immediately, and they should go to the nearest emergency department.
Does Plasil injection cause diarrhea?
Yes, diarrhea is a potential side effect of Plasil injection. This occurs because the drug’s primary mechanism of action is to increase and accelerate intestinal motility. While this effect is useful 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 Plasil injection be used for long periods?
Generally, it is recommended to use Plasil injection for the shortest possible duration (usually not exceeding 5 days). Long-term use (more than 3 months) is not typically recommended due to the increased risk of a serious side effect called “Tardive Dyskinesia.” This condition causes involuntary, repetitive movements, often in the face and mouth, and can be permanent even after stopping the medication.
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
- Purpose of Content: 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 and documented medical sources relevant to the topic (such as official drug leaflets, Ministry of Health 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.