Fentanyl (By injection)

Fentanyl (FEN-ta-nil)

Prevents or treats pain during and after surgery or other medical procedure. This is a narcotic pain medicine.

Brand Name(s):

When This Medicine Should Not Be Used:

How to Use This Medicine:

Injectable

• A doctor or other trained healthcare professional will give you this medicine in a hospital or surgery center. This medicine is given as a shot into a muscle or vein.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how fentanyl works. Tell your doctor if you are using any of the following:
  • Carbamazepine, cyclobenzaprine, erythromycin, ketoconazole, metaxalone, mirtazapine, nitrous oxide, phenytoin, rifampin, ritonavir, tramadol, or trazodone
  • Benzodiazepine medicine
  • Diuretic (water pill)
  • MAO inhibitor within the past 14 days
  • Medicine for depression, anxiety, or other mental health problems
  • Medicine for heart rhythm problems
  • Phenothiazine medicine
  • Triptan medicine for migraine headaches
• Do not drink alcohol while you are using this medicine.
• Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol. Tell your doctor if you are also using buprenorphine, butorphanol, nalbuphine, pentazocine, or a muscle relaxer.
• Do not eat grapefruit or drink grapefruit juice while you are using this medicine.

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, heart disease, heart rhythm problems, high or low blood pressure, lung or breathing problems (such as asthma, COPD, sleep apnea), adrenal problems, pancreas problems, or a history of brain tumor, head injury, seizures, or drug or alcohol abuse.
• This medicine may cause the following problems:
  • High risk of overdose, which can lead to death
  • Respiratory depression (serious breathing problem that can be life-threatening)
  • Sleep-related breathing problems (including sleep apnea, sleep-related hypoxemia)
  • High risk of muscle rigidity and movement
  • Serotonin syndrome, when used with certain medicines
  • Increased risk of heart rhythm problems, including QT prolongation
• This medicine may make you dizzy, drowsy, or lightheaded. Do not drive or do anything else that could be dangerous until you know how this medicine affects you. Sit or lie down if you feel dizzy. Stand up carefully.
• This medicine can be habit-forming. Do not use more than your prescribed dose. Call your doctor if you think your medicine is not working.
• Do not stop using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely.
• This medicine could cause infertility. Talk with your doctor before using this medicine if you plan to have children.
• This medicine may cause constipation, especially with long-term use. Ask your doctor if you should use a laxative to prevent and treat constipation.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Anxiety, restlessness, fast heartbeat, fever, sweating, muscle spasms, twitching, nausea, vomiting, diarrhea, seeing or hearing things that are not there
• Blue lips, fingernails, or skin
• Extreme dizziness or weakness, shallow breathing, slow or uneven heartbeat, sweating, cold or clammy skin, seizures
• Severe confusion, lightheadedness, dizziness, fainting
• Severe constipation, stomach pain, or vomiting
• Stiff or rigid muscles, tight feeling in your throat
• Trouble breathing or slow breathing
• Twitching or muscle movements you cannot control

If you notice these less serious side effects, talk with your doctor:

• Mild constipation
• Pain, itching, burning, swelling, or a lump under your skin where the shot was given

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 12/4/2023