Fentanyl medicine: uses, usage and Dosage


What is Fentanyl?

Fentanyl medicine is a strong opioid pain reliever. It is used to treat severe pain, such as during or after surgery or serious injury, or cancer pain.

Drug information fentanyl

  • Registration Number: VN-18441-14
  • Active ingredient: Fentanil
  • Dosage form: Solution for intramuscular injection or intravenous infusion
  • Packing: Box of 10 tubes x 2ml
  • Expiry date: 36 months
  • Group of analgesics – anti-inflammatory drugs

What forms and strengths of Fentanyl are available?

Fentanyl is available by prescription only. It has the form:

The patch is stuck on your skin

Lozenges and tablets that dissolve in the mouth

Nasal sprays

Injections (usually given only in the hospital)

fentanyl citrate injection ; injectable in combination with droperidol.

  • Syringe 2 ml, 5 ml, 10 ml, 20 ml (50 micrograms/ml); vials of 20, 30 and 50 ml (50 micrograms/ml).
  • The 2 ml syringe contains 50 micrograms of fentanyl and 2.5 mg of droperidol/ml.

How does fentanyl work?

The drug belongs to a class of drugs called opioid agonists. A drug class is a group of drugs that work in a similar way. These drugs are often used to treat similar conditions.

The drug works in your brain to change the way your body feels and reacts to pain.

Indications & contraindications for the use of fentanyl

Indication of drugs

Pain relief during and after surgery (respiratory support is required); support anesthesia and mechanical ventilation in resuscitation; combined with local anesthetic injected into the epidural and spinal cord.

Contraindications to the drug

  • The drug is contraindicated in patients with hypersensitivity to any of its components
  • The patient has a cesarean section (when the umbilical cord is not paired).
  • Respiratory failure without artificial ventilation
  • Are taking in combination with MAO inhibitors or within two weeks of discontinuing MAO inhibitors
  • Increased intracranial pressure and brain injury
  • Reduced blood flow and lower blood pressure
  • Severe muscle weakness
  • Children under 2 years old

What is the dose of fentanyl?

Dosage for adults 

Usual Adult Dose for Pain Before Surgery:

You will be given 50-100 mcg by intramuscular or slow intravenous injection about 30-60 minutes before surgery.

Usual Adult Dose for Local Anesthesia:

You will be given a slow intravenous injection of 25-100mcg over 1-2 minutes.

Usual Adult Dose for General Anesthesia:

For minor surgery, you will receive an intravenous dose of 0.5 – 2 mcg/kg.

For major surgery, you will be given an initial intravenous dose of 2-20 mcg/kg, then you will receive a maintenance dose of 1-2 mcg/kg every hour, stopping the infusion 30-60 minutes before At the end of surgery, limit the total dose of fentanyl to 10-15 mcg/kg for rapid monitoring and needle withdrawal.

For a corrected dose (rarely used), you will be given an intravenous dose of 20-50 mcg/kg.

Usual adult dose for pain relief (this indication has not been approved, you should limit its application):

You will receive a rapid intravenous infusion of 1-2 mcg/kg or a dose of 25-100mcg as needed or a continuous intravenous infusion of 1-2 mcg/kg per hour or 25-200 mcg per hour.

For severe pain, you will be given 50-100 mcg intravenously or intramuscularly every 1-2 hours as needed (patients who have used opioid pain relievers may need larger doses).

Dosage for children 

Dosage for children has not been studied and proven. This medicine may not be safe for children. You need to understand the safety of the drug before giving it to a child. Please consult your doctor or pharmacist for more details.

How to take fentanyl

Take the medicine exactly as prescribed by your doctor. Follow all directions on your medication label and read all medication instructions or instruction sheets. Your doctor may sometimes change your dose. Use the medication exactly as directed.

The effect of the drug fentanyl

It is one of the anesthetic analgesics commonly used to relieve severe pain or pain after surgery by acting on the brain or central nervous system.

Side effects of the drug fentanyl

Common side effects

  • Redness and irritation of the skin where you applied the patch
  • Nausea;
  • Vomiting;
  • Tired;
  • Dizziness;
  • Difficulty sleeping;
  • Constipation;
  • Increased sweating;
  • Feel cold;
  • Headache;
  • Diarrhea;
  • Loss of appetite;

These effects may go away within a few days or weeks.

Serious side effects

  • Breathe very shallowly
  • Fainting, dizziness, or confusion
  • Dizziness or lightheadedness, especially if you stand up too quickly
  • Jitter
  • Irritability or anxiety
  • Difficulty sleeping
  • Raise your blood pressure
  • Fast breathing rate
  • Fast heart beat
  • Dilated pupils (dark center of your eyes)
  • Nausea, vomiting and loss of appetite
  • Diarrhea and abdominal pain
  • Sweat
  • Chills or the hair on your arms “stands up”
  • Muscle pain and back pain

Adrenal failure. Symptoms may include:

  • Prolonged fatigue
  • Muscle weakness
  • Stomachache

Androgen deficiency. Symptoms may include:

  • Tired
  • Difficulty sleeping
  • Reduced energy

Fentanyl interactions 

The drug may interact with certain other drugs. Different interactions can cause different effects. For example, some can affect how well a drug works, while others can cause increased side effects.

Medicines you should not take with fentanyl

Do not take these medicines with fentanyl. Taking medicine with these medicines can cause dangerous effects on your body. Examples of these drugs include:

Buprenorphine: Taking this medicine with fentanyl may decrease its effects, cause withdrawal symptoms, or both.

Depression medications such as monoamine oxidase inhibitors (MAOIs): Taking these drugs with fentanyl can cause anxiety, confusion, slow breathing, or coma. Do not take fentanyl if you are taking MAOIs or have taken MAOIs within the past 14 days.

Interactions increase the risk of side effects

Taking fentanyl with certain medications can increase negative effects. Examples of these drugs include:

Muscle relaxants, such as baclofen, cyclobenzaprine, and methocarbamol.

You may experience increasing breathing problems.

Hypnotics, such as zolpidem, temazepam, and estazolam.

You may experience breathing problems, low blood pressure, drowsiness, or a coma. Your doctor may prescribe a lower dose for you.

Anticholinergics, such as atropine, scopolamine, and benztropine.

You may have more problems urinating or have severe constipation, which can lead to more serious bowel problems.

Voriconazole and ketoconazole: These drugs can increase the level of fentanyl in your body, which may increase your risk of side effects. Your doctor may monitor you more often and adjust your dosage as needed.

Erythromycin: This drug may increase the levels of fentanyl in your body, which may increase your risk of side effects. Your doctor may monitor you more often and adjust your dosage as needed.

Ritonavir: This medicine may increase the levels of fentanyl in your body, which may increase your risk of side effects. Your doctor may monitor you more often and adjust your dosage as needed.

Interactions that can make the drug less effective

When using fentanyl with certain medicines, it may not work to treat your condition. 

Rifampin: This medicine can lower the levels of it in your body, making fentanyl less effective at relieving your pain. Your doctor may monitor you more often and adjust your dosage as needed.

Carbamazepine, phenobarbital, and phenytoin: These drugs can lower the level of the drug in your body, making fentanyl less effective at relieving your pain. Your doctor may monitor you more often and adjust your dosage as needed.

Precautions while using fentanyl

  • Note Fentanyl is not effective in the management of acute and postoperative pain.
  • Patients may experience respiratory distress after the patch is removed.
  • The drug may increase respiratory depression due to the drug acting on the central nervous system.
  • Patients can develop chronic lung disease when using the drug.
  • Drug addiction.
  • Patients with brain tumors should be careful when using the drug, because the drug can increase intracranial pressure. Therefore, for these cases, it is necessary to get the consent of the doctor to use it.
  • Patients with heart disease also need to be careful when using the drug.
  • The drug should be limited to patients with liver disease and kidney disease.
  • Fentanyl may affect the patient’s ability to drive and use machines.
  • Pregnant and nursing women should not take Fentanyl because it is excreted in breast milk, which will affect the baby.
  • When any side effects occur after removing the patch, the patient should be monitored within 24 hours.
  • The elderly and children also need to be careful when using the drug.

How much does fentanyl cost?

The price of fentanyl will have a certain fluctuation between pharmacies and distribution agents. Users can consult prices directly at reputable drugstores nationwide.

How to store medicine?

  • You should store the medicine at room temperature, in a cool, dry place, away from direct sunlight.
  • You should not store the medicine in the refrigerator.
  • Keep the medicine out of the reach of children.
  • Do not throw medicine down the toilet or plumbing.

Note: The  above information about fentanyl related to the drug’s effects and usage is for the purpose of sharing knowledge, introducing drug information for medical staff and patients to refer to. Each case and location will have its own prescription and treatment. Patients must not arbitrarily use drugs, all information on drug use must be prescribed by a specialist doctor.


See also: https://index-china.com/fentanyl-medicine/

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