In the U.S.—

In Canada—

• Analgesic

Fentanyl ( FEN-ta-nil) belongs to the group of medicines called narcotic analgesics (nar-KOT-ik an-al-GEE-ziks ) . Narcotic analgesics are used to relieve pain. The transdermal system (skin patch) form of fentanyl is used to treat chronic pain (pain that continues for a long time).

Fentanyl acts in the central nervous system (CNS) to relieve pain. Some of its side effects are also caused by actions in the CNS.

When a narcotic is used for a long time, it may become habit-forming (causing mental or physical dependence). However, people who have continuing pain should not let the fear of dependence keep them from using narcotics to relieve their pain. Mental dependence (addiction) is not likely to occur when narcotics are used for this purpose. Physical dependence may lead to withdrawal side effects if treatment is stopped suddenly. However, severe withdrawal side effects can usually be prevented by reducing the dose gradually over a period of time before treatment is stopped completely.

This medicine is available only with your doctor's prescription. Prescriptions for transdermal fentanyl cannot be refilled. You will need to obtain a new prescription from your doctor each time you need the medicine. This medicine is available in the following dosage form:

Transdermal
• Transdermal system (stick-on skin patch) (U.S. and Canada)

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your health care professional will make. For fentanyl, the following should be considered:

Allergies—Tell your health care professional if you have ever had any unusual or allergic reaction to fentanyl, alfentanil (e.g., Alfenta), or sufentanil (e.g., Sufenta). Also tell your health care professional if you are allergic to any other substances, including the adhesives that keep stick-on bandages in place.

Pregnancy—Although studies on birth defects with fentanyl have not been done in pregnant women, it has not been reported to cause birth defects. However, using any narcotic regularly during pregnancy may cause physical dependence in the fetus. This may lead to withdrawal side effects after birth. Also, use of this medicine near the end of pregnancy may cause drowsiness and breathing problems in newborn babies.

Breast-feeding—Fentanyl passes into the breast milk. Nursing babies whose mothers are using this medicine regularly may receive enough of it to cause unwanted effects such as drowsiness, breathing problems, and physical dependence. Similar effects may also occur with some other narcotics if they are taken regularly in large amounts. A mother who wishes to breast-feed and who needs treatment for continuing pain should discuss the risks and benefits of different pain treatments with her health care professional.

Children—Studies with the fentanyl skin patch have been done only in adult patients, and there is no specific information comparing the use of this medicine in children with use in other age groups.

Older adults—Elderly people are especially sensitive to the effects of narcotic analgesics. This may increase the chance of side effects, especially breathing problems, during treatment. Your health care professional will take this into consideration when deciding on the amount of transdermal fentanyl you should receive.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your health care professional may want to change the dose, or other precautions may be necessary. When you are using fentanyl, it is especially important that your health care professional know if you are taking any of the following:

• Buprenorphine (e.g., Buprenex) or
• Dezocine (e.g., Dalgan) or
• Nalbuphine (e.g., Nubain) or
• Pentazocine (e.g., Talwin)—Like all narcotic analgesics, these medicines may add to the effects of fentanyl, which may increase the chance of side effects or overdose. However, buprenorphine, dezocine, nalbuphine, and pentazocine sometimes decrease the effects of fentanyl, so that fentanyl might be less effective in relieving pain. Also, these medicines can cause withdrawal side effects if they are given to someone who is physically dependent on fentanyl

• CYP3A4 (an isoenzyme that breaks down fentanyl in the body) inducers such as:
  • Carbamazepine (e.g., Tegretol) or
  • Phenytoin (e.g., Dilantin) or
  • Rifampin (e.g., Rifadin)—Giving these medicines with fentanyl will decrease the pain-relieving effects of fentanyl.

• CYP3A4 inhibitors such as:
  • Azole antifungal agents (e.g., ketoconazole (Nizoral)) or
  • Macrolide antibiotics (e.g., erythromycin or
  • Protease inhibitors (ritonavir (Norvir))—Giving these medicines with fentanyl may cause too much fentanyl in your blood.

• Central nervous system (CNS) depressants (medicines that cause drowsiness), including other narcotics, or
• Tricyclic antidepressants—These medicines may add to the effects of fentanyl. This may increase the chance of serious side effects

• Naltrexone (e.g., Trexan)—Fentanyl will not be effective in people taking naltrexone

• Alcohol abuse, or history of, or
• Drug dependence, especially narcotic abuse or dependence, or history of, or
• Emotional problems or
• Kidney disease or
• Liver disease or
• Underactive thyroid—The chance of side effects may be increased

• Brain tumor or
• Diarrhea caused by antibiotic treatment or poisoning or
• Emphysema, asthma, or other chronic lung disease or
• Enlarged prostate or problems with urination or
• Gallbladder disease or gallstones or
• Intestinal problems such as colitis or Crohn's disease—Some of the side effects of fentanyl can cause serious problems in people who have these medical problems

• Slow heartbeat—Fentanyl can make this condition worse

Transdermal fentanyl comes with patient instructions. Read them carefully before using the product. If you do not receive any printed instructions with the medicine, check with your pharmacist.

To use:

• Use this medicine exactly as directed by your doctor. It will work only if it has been applied correctly.
• Fentanyl skin patches are packaged in sealed pouches. Do not remove the patch from the sealed pouch until you are ready to apply it.
• When handling the skin patch, be careful not to touch the adhesive (sticky) surface with your hand. The adhesive part of the system contains some fentanyl, which can be absorbed into your body too fast through the skin of your hand. If any of the medicine does get on your hand, rinse the area right away with a lot of clear water. Do not use soap or other cleansers.
• Be careful not to tear the patch or make any holes in it. Damage to a patch may allow fentanyl to pass into your skin too quickly. This can cause an overdose.
• Apply the patch to a dry, flat skin area on your upper arm, chest, or back. Choose a place where the skin is not very oily and is free of scars, cuts, burns, or any other skin irritations. Also, do not apply this medicine to areas that have received radiation (x-ray) treatment .
• The patch will stay in place better if it is applied to an area with little or no hair. If you need to apply the patch to a hairy area, you may first clip the hair with scissors, but do not shave it off.
• If you need to clean the area before applying the medicine, use only plain water. Do not use soaps, other cleansers, lotions, or anything that contains oils or alcohol. Be sure that the skin is completely dry before applying the medicine.
• Remove the liner covering the sticky side of the skin patch. Then press the patch firmly in place, using the palm of your hand, for a minimum of 30 seconds. Make sure that the entire adhesive surface is attached to your skin, especially around the edges.
• If the patch becomes loose, tape the edges with first aid tape.
• If the patch falls off after applying it, throw it away and apply a new patch in a different area.
• If you need to apply more than 1 patch at a time, place the patches far enough apart so that the edges do not touch or overlap each other.
• Wash your hands with a lot of clear water after applying the medicine. Do not use soap or other cleansers.
• Remove the patch after 72 hours (3 days), or as directed by your doctor. Choose a different place on your skin to apply the next patch. If possible, use a place on the other side of your body. Wait at least 3 days before using the first area again.

After a patch is applied, the fentanyl it contains passes into the skin a little at a time. A certain amount of the medicine must build up in the skin before it is absorbed into the body. Therefore, up to a day may pass before the first dose begins to work. Your health care professional may need to change the dose during the first several applications (each kept in place for 3 days) before finding the amount that works best for you. Even if you feel that the medicine is not working, do not increase the amount of transdermal fentanyl that you apply. Instead, check with your health care professional.

You will probably need to take a faster-acting narcotic to relieve pain during the first few days of transdermal fentanyl treatment. You may continue to need another narcotic while your dose of fentanyl is being adjusted, and also to relieve any "breakthrough" pain that occurs later on. Be sure that you do not take more of the other narcotic, and do not take it more often, than directed. Taking other narcotics together with fentanyl can increase the chance of an overdose.

Dosing—

The dose of transdermal fentanyl will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

• For transdermal dosage form (stick-on patch):
  • For relief of severe, continuing pain:
    • Adults—If you have not already been using other narcotics regularly, your first dose will probably be one patch that releases 25 micrograms (mcg) of fentanyl every hour. If you have already been using other narcotics regularly, your first dose will depend on the amount of other narcotic you have been taking every day. If necessary, your health care professional will change the dose after 3 days, when the first patch is replaced. The size of the new dose will depend on how well the medicine is working and on whether you had any side effects during the first 3-day application. Other changes in dose may be needed later on. Some people may need to use more than one patch at a time.
    • Children—Use and dose must be determined by the doctor.

Missed dose—

If you miss a dose of this medicine, apply it as soon as possible. Remove the new patch 3 days after applying it.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not keep outdated medicine or medicine no longer needed. To dispose of this medicine, first fold the patch in half, with the sticky side inside. If the patch has not been used, take it out of the pouch and remove the liner that covers the sticky side of the patch before folding it in half. Then flush it down the toilet right away.

Check with your health care professional at regular times while using fentanyl. Be sure to report any side effects.

After you have been using this medicine for a while, "breakthrough" pain may occur more often than usual, and it may not be relieved by your regular dose of medicine. If this occurs, do not increase the amount of transdermal fentanyl or other narcotic that you are taking without first checking with your health care professional.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that can make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; other prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. You will probably be directed to take other pain relievers if you still have pain while using transdermal fentanyl. However, check with your health care professional before taking any of the other medicines listed above while you are using this medicine .

Fentanyl may cause some people to become drowsy, dizzy, or lightheaded, or to feel a false sense of well-being. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert and clearheaded . These effects usually go away after a few days of treatment, when your body gets used to the medicine. However, check with your health care professional if drowsiness that is severe enough to interfere with your activities continues for more than a few days.

Dizziness, lightheadedness, or even fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve dizziness or lightheadedness.

Nausea or vomiting may occur, especially during the first several days of treatment. Lying down for a while may relieve these effects. However, if they are especially bothersome or if they continue for more than a few days, check with your health care professional. You may be able to take another medicine to help prevent these problems.

Using narcotics for a long time can cause severe constipation. To prevent this, your health care professional may direct you to take laxatives, drink a lot of fluids, or increase the amount of fiber in your diet. Be sure to follow the directions carefully, because continuing constipation can lead to more serious problems.

Heat can cause the fentanyl in the patch to be absorbed into your body faster. This may increase the chance of serious side effects or an overdose. While you are using this medicine, do not use a heating pad, a sunlamp, or a heated water bed, and do not take sunbaths or long baths or showers in hot water. Also, check with your health care professional if you get a fever.

Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are using this medicine. Serious side effects can occur if your medical doctor or dentist gives you certain other medicines without knowing that you are using fentanyl.

You may bathe, shower, or swim while wearing a fentanyl skin patch. However, be careful to wash and dry the area around the patch gently. Rubbing may cause the patch to get loose or come off. If this does occur, throw away the patch and apply a new one in a different place. Make sure the area is completely dry before applying the new patch.

If you have been using this medicine regularly for several weeks or more, do not suddenly stop using it without first checking with your health care professional. You may be directed to reduce gradually the amount you are using before stopping treatment completely, or to take another narcotic for a while, to lessen the chance of withdrawal side effects.

Using too much transdermal fentanyl, or taking too much of another narcotic while using transdermal fentanyl, may cause an overdose. If this occurs, get emergency help right away. An overdose can cause severe breathing problems (breathing may even stop), unconsciousness, and death. Serious signs of an overdose include very slow breathing (fewer than 8 breaths a minute) and drowsiness that is so severe that you are not able to answer when spoken to or, if asleep, cannot be awakened. Other signs of an overdose may include cold, clammy skin; low blood pressure; pinpoint pupils of eyes; and slow heartbeat. It may be best to have a family member or a friend check on you several times a day when you start using a narcotic regularly, and whenever your dose is increased, so that he or she can get help for you if you cannot do so yourself.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Get emergency help immediately if the following signs of overdose occur:

• Cold, clammy skin;  convulsions (seizures) ;  drowsiness that is so severe that you are not able to answer when spoken to or, if asleep, cannot be awakened;  low blood pressure;  pinpoint pupils of eyes;  slow heartbeat;  very slow (fewer than 8 breaths a minute) or troubled breathing 

Also, check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Decrease in amount of urine or in the frequency of urination ;  hallucinations (seeing, hearing, or feeling things that are not there) 
  
  

• Less common
  • Chest pain;  difficulty in speaking;  fainting;  irregular heartbeat;  mood or mental changes;  problems with walking;  redness, swelling, itching, or bumps on the skin at place of application;  spitting blood  
  
  

• Rare
  • Any change in vision;  bladder pain;  difficulty in speaking;  fever with or without chills;  fluid-filled blisters on skin;  frequent urge to urinate;  noisy breathing, shortness of breath, tightness in chest, or wheezing;  red, thickened, or scaly skin;  swelling of abdomen or stomach area;  swollen and/or painful glands;  unusual bruising 
  
  

• Incidence not known
  • Bloating or swelling of face, hands, lower legs and/or feet;  rapid weight gain;  fast or pounding heartbeat or pulse 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Abdominal or stomach pain that was not present before treatment ;  confusion;  constipation ;  diarrhea;  dizziness, drowsiness, or lightheadedness;  false sense of well-being;  feeling anxious;  headache;  indigestion;  loss of appetite;  nausea or vomiting;  nervousness;  sweating;  weakness 
  
  

• Less common
  • Bloated feeling or gas;  feeling anxious and restless at the same time;  feeling of crawling, tingling, or burning of the skin;  memory loss;  unusual dreams 
  
  

• Incidence not known
  • Weight loss 
  
  

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor if you notice any of the following side effects:

• Anxiety;  body aches;  diarrhea;  fast heartbeat;  fever, runny nose, or sneezing;  gooseflesh;  increased sweating;  increased yawning ;  loss of appetite;  nausea or vomiting;  nervousness, restlessness, or irritability ;  shivering or trembling;  stomach cramps;  trouble in sleeping;  unusually large pupils of eyes;  weakness  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.