Fentanyl citrate is an opioid pain medicine used to treat "breakthrough" cancer pain that is not controlled by other medicines. fentanyl citrate is not for treating pain that is not cancer-related.

Fentanyl citrate is for use in adults and teenagers who are at least 16 years old.

Fentanyl citrate may also be used for purposes not listed in this medication guide.

MISUSE OF OPIOID MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it.

Do not use fentanyl citrate unless you are already using an around-the-clock opioid medicine and are tolerant to it.

Using opioid medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.

Fatal side effects can occur if you use this medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.

Follow the directions on your prescription label and read all medication guides. Never use fentanyl in larger amounts, or for longer than prescribed. Tell your doctor if you feel an increased urge to take more of fentanyl citrate.

Never share opioid medicine with another person, especially someone with a history of drug abuse or addiction. MISUSE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it. Selling or giving away opioid medicine is against the law.

If you switch from using fentanyl citrate to using other forms of fentanyl, you will not use the same dose. If you use the same dose of each medication, you may have life-threatening overdose symptoms.

Do not stop using any other pain medicines your doctor has prescribed for you.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Do not eat or drink anything while a fentanyl citrate unit is in your mouth. You must not use more than 2 units of this medicine to treat an episode of breakthrough cancer pain. Use only 1 unit at a time.

Pay special attention to your dental hygiene. Fentanyl citrate can cause dry mouth leading to tooth decay.

Do not stop using fentanyl citrate suddenly, or you could have unpleasant withdrawal symptoms. Ask your doctor how to safely stop using this medicine.

Store at room temperature away from moisture and heat. Leave each unit in its child-proof blister pack until you are ready to use it.

Keep track of your medicine. You should be aware if anyone is using it improperly or without a prescription.

Keep both used and unused fentanyl citrate units out of the reach of children or pets. The amount of fentanyl citrate in one unit can be fatal to a child who accidentally sucks on or swallows the unit. Seek emergency medical attention if this happens.

Do not keep leftover opioid medication. Just one dose can cause death in someone using this medicine accidentally or improperly. Ask your pharmacist where to locate a drug take-back disposal program. If there is no take-back program, follow the instructions provided with this medicine when disposing of unused medicine.

Do not use fentanyl unless you are already using an around-the-clock opioid medicine and are tolerant to it. You should not use fentanyl if you are allergic to it, or if you have:

• severe asthma or other breathing problems; or

• a stomach or bowel obstruction (including paralytic ileus).

Do not give fentanyl citrate to any person who does not have a personal prescription for this medicine.

Tell your doctor if there are children living in the home where you will store this medicine. The amount of fentanyl in one transmucosal unit can be fatal to a child.

Tell your doctor if you have ever had:

• breathing problems, sleep apnea;

• a head injury, brain tumor, or mental illness;

• alcoholism or drug addiction;

• a seizure disorder;

• liver or kidney disease; or

• low blood pressure, heart disease, slow heartbeats.

If you use opioid medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on opioids may need medical treatment for several weeks.

Do not breast-feed while you are using fentanyl citrate.

Since fentanyl is used for pain, you are not likely to miss a dose. Skip any missed dose if it is almost time for your next dose. Do not use two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. A fentanyl overdose can be fatal, especially in a child or other person using the medicine without a prescription. Overdose symptoms may include slow breathing and heart rate, severe drowsiness, muscle weakness, cold and clammy skin, pinpoint pupils, and fainting.

Do not drink alcohol. Dangerous side effects or death could occur.

Avoid driving or operating machinery until you know how fentanyl citrate will affect you. Dizziness or severe drowsiness can cause falls or other accidents.

Grapefruit may interact with fentanyl citrate and lead to unwanted side effects. Avoid the use of grapefruit products.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Remove this medicine from your mouth and call your doctor at once if you have:

• slow heart rate, sighing, shallow breathing, breathing that stops during sleep;

• severe drowsiness, feeling like you might pass out;

• dizziness or an upset stomach before the medicine has completely dissolved;

• confusion, extreme fear, unusual thoughts or behavior; or

• low cortisol levels--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Serious side effects may be more likely in older adults and those who are overweight, malnourished, or debilitated.

Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.

Common side effects of fentanyl citrate may include:

• dizziness, mild drowsiness, depressed mood;

• sleep problems (insomnia);

• headache, weakness, anxiety;

• nausea, vomiting, constipation; or

• mild rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

You may have breathing problems or withdrawal symptoms if you start or stop taking certain other medicines. Tell your doctor if you also use an antibiotic, antifungal medication, heart or blood pressure medication, seizure medication, or medicine to treat HIV or hepatitis C.

Opioid medication can interact with many other drugs and cause dangerous side effects or death. Be sure your doctor knows if you also use:

• cold or allergy medicines, bronchodilator asthma/COPD medication, or a diuretic ("water pill");

• medicines for motion sickness, irritable bowel syndrome, or overactive bladder;

• other narcotic medications--opioid pain medicine or prescription cough medicine;

• a sedative like Valium--diazepam, alprazolam, lorazepam, Xanax, Klonopin, Versed, and others;

• drugs that make you sleepy or slow your breathing--a sleeping pill, muscle relaxer, medicine to treat mood disorders or mental illness; or

• drugs that affect serotonin levels in your body--a stimulant, or medicine for depression, Parkinson's disease, migraine headaches, serious infections, or nausea and vomiting.

This list is not complete. Other drugs may affect fentanyl citrate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.