fentanyl injection

Medically Reviewed on 2/17/2023

Generic Name: fentanyl 

Brand Name: Sublimaze

Drug Class: Opioid Analgesics, Synthetic, Opioids

What is fentanyl, and what is it used for?

Fentanyl is a strong, synthetic (man-made) narcotic that is similar to morphine.

A 0.1 mg dose of fentanyl is approximately equal to 10 mg of morphine administered by intramuscular injection. Fentanyl stimulates receptors on nerves in the brain to increase the threshold of pain (the amount of stimulation it takes to feel pain) and reduce the perception of pain (the perceived importance of the pain).

Fentanyl is available in transdermal (for application to the skin), transmucosal (for application to mucus membranes), and parenteral (injectable) forms. Fentanyl was originally approved by the FDA for injection in 1968.

What are the side effects of fentanyl?

Fentanyl is a controlled substance and is habit forming. Mental and physical dependence can occur. Abruptly stopping the drug in patients who have been taking the drug for a long time can precipitate a withdrawal reaction. Symptoms of withdrawal include nausea, diarrhea, coughing, tearing, nasal discharge, profuse sweating, twitching muscles, and yawning.

Fentanyl can cause respiratory depression (decreased rate or depth of breathing), muscle rigidity, and reduced heart rate.

Additional side effects are:

Other important side effects include:

What is the dosage for fentanyl?

  • Fentanyl injection can be injected into a muscle (intramuscular) or into veins (intravenous).
  • The usual dose for surgical premedication in adults is 0.05 mg to 0.1 mg per dose given by intramuscular injection or by intravenous injection.
  • For anesthesia, the dose is 0.5 to 20 mcg/kg per dose given intravenously.
  • A maintenance intravenous infusion of 1-2 mcg/kg/hour also may be used.
  • There are several recommended regimens for treating pain.
  • Fentanyl also is used for patient-controlled anesthesia (PCA).

Which drugs interact with fentanyl?


Medically speaking, the term "myalgia" refers to what type of pain? See Answer

Pregnancy and breastfeeding

  • Fentanyl can cross the placenta and enter the fetus. Effects on the developing fetus are not known; however, fentanyl can slow breathing in newborn infants whose mothers were exposed to fentanyl. Routine use of fentanyl by pregnant women can lead to withdrawal reactions in the newborn. Thus, caution should be used if fentanyl is administered near the time of delivery.
  • The effects of fentanyl on the infants of mothers who nurse is unknown. Since most drugs are concentrated in breast milk, it is advisable that women requiring fentanyl bottle-feed their infants.

What else should I know about fentanyl?

What preparations of fentanyl are available?
  • Injection Solution: 0.05 mg/ml
How should I keep fentanyl stored?
  • Fentanyl injection should be stored at room temperature 20 C to 25 C (68 F to 77 F) and protect it from light.


Fentanyl injection is a synthetic narcotic similar to morphine. Fentanyl injection is prescribed to reduce pain before, during, or after surgery. It also is used for treating severe pain that is unrelated to surgery. Fentanyl is a controlled substance and is habit forming. Fentanyl can cause respiratory depression (decreased rate or depth of breathing), muscle rigidity, and reduced heart rate. Side effects of fentanyl injection include nausea, vomiting, constipation, drowsiness, and itching.

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Medically Reviewed on 2/17/2023
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