Fentanyl injection
Fentanyl injection
What is this medicine?
FENTANYL (FEN ta nil) is a pain reliever. It is used to treat pain before, during, and after surgery. This medicine is also used before, with, and in place of other medicines for sleep during a medical procedure.
How should I use this medicine?
This medicine is for injection into a vein or muscle. It is given by a health care professional in a hospital or clinic setting.
Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.
What side effects may I notice from receiving this medicine?
Side effects that you should report to your doctor or health care professional as soon as possible:
allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
breathing problems
confusion
signs and symptoms of low blood pressure like dizziness; feeling faint or lightheaded, falls; unusually weak or tired
trouble passing urine or change in the amount of urine
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
constipation
dry mouth
nausea, vomiting
tiredness
What may interact with this medicine?
Do not take this medication with any of the following medicines:
mifepristone
This medicine may also interact with the following medications:
alcohol
antihistamines for allergy, cough and cold
antiviral medicines for HIV or AIDS
aprepitant
atropine
certain antibiotics like erythromycin and clarithromycin
certain medicines for anxiety or sleep
certain medicines for bladder problems like oxybutynin, tolterodine
certain medicines for blood pressure, heart disease, irregular heart beat
certain medicines for depression like amitriptyline, fluoxetine, sertraline
certain medicines for diabetes like pioglitazone, troglitazone
certain medicines for fungal infections like ketoconazole and itraconazole
certain medicines for seizures like phenobarbital, phenytoin, primidone
certain medicines for stomach problems like dicyclomine, hyoscyamine
certain medicines for travel sickness like scopolamine
certain medicines for Parkinson's disease like benztropine, trihexyphenidyl
cimetidine
general anesthetics like halothane, isoflurane, methoxyflurane, propofol
grapefruit juice
ipratropium
local anesthetics like lidocaine, pramoxine, tetracaine
MAOIs like Carbex, Eldepryl, Marplan, Nardil, and Parnate
medicines that relax muscles for surgery
other narcotic medicines for pain or cough
phenothiazines like chlorpromazine, mesoridazine, prochlorperazine, thioridazine
rifampin
St. John's wort
steroid medicines like prednisone or cortisone
What if I miss a dose?
This does not apply.
Where should I keep my medicine?
This drug is given in a hospital or clinic and will not be stored at home.
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
brain tumor
breathing problems
drug abuse or addiction
head injury
kidney disease
liver disease
use of a MAOI like Carbex, Eldepryl, Marplan, Nardil, and Parnate in the past 14 days
an unusual or allergic reaction to fentanyl, other opioid analgesics, other medicines, foods, dyes, or preservatives
pregnant or trying to get pregnant
breast-feeding
What should I watch for while using this medicine?
Tell your doctor or health care professional if your pain does not go away, if it gets worse, or if you have new or a different type of pain. You may develop tolerance to the medicine. Tolerance means that you will need a higher dose of the medicine for pain relief. Tolerance is normal and is expected if you take the medicine for a long time.
Do not suddenly stop taking your medicine because you may develop a severe reaction. Your body becomes used to the medicine. This does NOT mean you are addicted. Addiction is a behavior related to getting and using a drug for a non-medical reason. If you have pain, you have a medical reason to take pain medicine. Your doctor will tell you how much medicine to take. If your doctor wants you to stop the medicine, the dose will be slowly lowered over time to avoid any side effects.
There are different types of narcotic medicines (opiates). If you take more than one type at the same time or you are taking another medicine that also causes drowsiness, you may have more side effects. Give your health care provider a list of all medicines you use. Your doctor will tell you how much medicine to take. Do not take more medicine than directed. Call emergency for help if you have problems breathing or unusual sleepiness.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effects of this medicine. Avoid alcoholic drinks.
This medicine will cause constipation. Try to have a bowel movement at least every 2 to 3 days. If you do not have a bowel movement for 3 days, call your doctor or health care professional.
Your mouth may get dry. Chewing sugarless gum or sucking hard candy, and drinking plenty of water may help. Contact your doctor if the problem does not go away or is severe.
Updated:  
July 17, 2018