Fentanyl (buccal mucosa, sromucosal, sublingual)


Many cancer patients experience a situation called break-through pain, which involves pain flares that burst through the patient's regular pain medication. This medication is only available with a prescription and, because it is classed as a narcotic analgesic, some types of the drug, such as Fentora, Subsys, Onsolis, Actiq and Abstral are included in the federal restricted distribution program. This program requires patients to review, agree to and sign papers of agreement when they receive their prescription.

This drug affects the central nervous system, often referred to as the CNS, which can cause certain side effects. Many people avoid narcotics due to the likelihood of addiction, which can be both mental and physical. However, patients who suffer from severe pain may need to put those fears aside, as narcotics can be one of the more effective drug options in the treatment of severe pain. If patients do develop a physical dependence on this medication, their medical team can work with them to help minimize the effects of withdrawal. It is important that patients do not stop taking this medication quickly or without medical supervision.

Patients who are experiencing extreme pain may be less likely to develop a psychological dependence on this medication. If you are concerned about the potential for dependency developing while taking this medication, be sure to discuss your concerns with your doctor.

Fentanyl has been reported to cause overdose. Patients taking this medication, and their caregivers, need to be fully aware of the signs and symptoms of overdose and seek immediate emergency attention should they occur. Patients and their primary caregivers are advised to work closely with the prescribing physician to ensure that all possible measures are taken to avoid unwanted side effects.

Fentanyl is offered in the following delivery methods: spray, lozenge, film and tablet.

Conditions Treated

  • Extreme pain in cancer patients

Type Of Medicine

  • Analgesic
  • Opioid

Side Effects

As with many medications, there are certain side effects that can potentially occur while you are taking fentanyl. If you experience one or more of the symptoms listed below, it is important that you notify your doctor right away, as they can be a sign of a more serious problem.

More likely:

  • Black, tarry stools
  • Unusual bleeding or bruising
  • Chest pain
  • Troubled breathing with exertion
  • Convulsions
  • Swelling of the hands, ankles, feet or lower legs
  • Decreased urine
  • A sore throat
  • Dizziness
  • Rapid breathing
  • Fainting
  • Pale skin
  • Increased thirst
  • Numbness or tingling in the hands, feet or lips
  • Lightheadedness
  • Nausea or vomiting
  • Lower back or side pain
  • Sunken eyes
  • Muscle pain or cramps
  • Mood changes
  • Nervousness
  • Loss of appetite
  • Painful or difficult urination
  • Irregular heartbeat
  • Pounding in the ears
  • Fever or chills
  • Sneezing
  • Dry mouth
  • Confusion
  • Difficult or labored breathing
  • Tightness in the chest
  • Coughing
  • Ulcers, sores, or white spots in the mouth
  • Unusual tiredness or weakness
  • Blurred vision
  • Wrinkled skin

Less likely:

  • Abdominal or stomach pain
  • Slow or fast heartbeat
  • Rhythmic movement of the muscles
  • Clumsiness or unsteadiness
  • Severe sleepiness
  • Change in walking and balance
  • Seizures
  • Muscle twitching or jerking
  • Decreased frequency of urination
  • Seeing, hearing or feeling things that are not there
  • Pounding in the ears
  • Severe constipation
  • Headaches
  • Shakiness in the legs, arms, hands or feet
  • Decreased awareness or responsiveness
  • Thinking abnormalities
  • Trembling or shaking of the hands or feet

Overdose symptoms that require immediate emergency attention:

  • Slow breathing
  • Extremely shallow breathing

As your body adjusts to the fentanyl that is building up in your system, you may experience some effects that will likely go away on their own after a few days. If you experience any of the side effects that are listed below and they do not dissipate or become worse over time, it is advisable to notify your doctor. In some cases, your doctor may believe that additional medical attention is necessary.

More likely:

  • Back pain
  • Trouble concentrating
  • Weight loss
  • Loss of interest or pleasure
  • Difficulty having a bowel movement
  • Sleepiness or unusual drowsiness
  • Discouragement
  • Muscle stiffness
  • Irritability
  • Diarrhea
  • Lack or loss of strength
  • Pain in the joints
  • Feeling sad or empty
  • Tiredness
  • Difficulty moving
  • Trouble sleeping

Less likely:

  • Changes in vision
  • Rash
  • Excessive muscle tone
  • Feeling of constant movement of self or surroundings
  • Itching skin
  • Sensation of spinning
  • Irritation, pain, or sores at the site of application
  • Flushing or redness of the skin, especially on the face and neck
  • Muscle tension or tightness
  • Feeling of warmth or heat
  • Sweating

Unknown likelihood:

  • Dental trouble
  • Tooth pain
  • Gum trouble

While the above list is comprehensive in nature, it is possible that you may experience other symptoms. Any time that you have concerns about taking fentanyl, it is best to speak to your prescribing physician or pharmacist.


The information below is only included to provide an overview of the typical dosage amounts and frequencies. If your doctor has advised you to take fentanyl in different amounts or frequencies, it is important that you always follow their instructions.

Several brand names that contain fentanyl are classed as restricted, and you will be required to complete additional paperwork when you pick up your prescription:

  • Fentora
  • Abstral
  • Onsolis
  • Actiq
  • Subsys

Your physician will prescribe you a specific brand, and it is important that you take that medication, as different medications can react differently in your system.

Always store the medication in the original blister package and do not open the medicine until just before taking it.

For patients who have been prescribed Abstral® sublingual:

Do not swallow this tablet, suck on it or chew it; the tablet should be placed under the tongue to dissolve. Do not eat or drink anything while you are waiting for the medicine to dissolve. If you are experiencing dry mouth, be sure to do a quick water rinse prior to taking this medication.

If you have been prescribed the Actiq® lozenges:

This lozenge must completely dissolve in your mouth, which may take up to 15 minutes. Be sure that you do not bite into or chew the lozenge. When taking the medication, it is advised that you put it between your inner cheek and lower gum. If you want to move the lozenge from one side of the mouth to the other, be sure to use the handle and do not touch the medication with your fingers.

Patients who are taking Fentora® buccal tablets:

Buccal tablets can take up to 30 minutes to dissolve and it is important that they are not chewed or swallowed. Do not actively suck on the tablet; place in the upper back quadrant of your mouth, preferably above a molar. If, after 30 minutes of waiting, the tablet has not completely dissolved, it is advised that you swallow the remainder with a glass of water.

When removing the tablet from the blister pack, be certain to peel back the protective foil rather than attempting to push the tablet through the blister containment.

Patients using Onsolis® buccal film:

Be sure that your hands and fingers have been cleaned and are completely dry. Moisten the interior of your mouth, whether with your tongue or with water. Remove the film from its packaging and place it on your finger with the pink side up. Using your finger, place the film firmly against one cheek on the moistened spot and hold for five seconds. Keep the film firmly in place until it dissolves fully.

Do not swallow or chew the medication. If your dosage calls for another piece of film, it is advised that it be placed on the opposite cheek. It is important to avoid eating while you are waiting for the film to dissolve; it is okay to drink water or another beverage after waiting for a period of at least five minutes.

If you have been prescribed Subsys® sublingual spray:

This medication is administered via a sublingual spray (i.e you spray the medication under your tongue). Once you have sprayed the Subsys, wait 30 to 60 seconds before moving your tongue. It is important that you do not drink anything, spit out the medication or rinse your mouth immediately after you have sprayed the Subsys.

The guidelines that are described below relate to the typical amounts and frequencies with which these medications are taken. Always follow the instructions that are provided to you by your prescribing physician, even if they differ from the typical dosages.

Typical dosage information for the use of fentanyl in the treatment of cancer pain:

Buccal film:

Patients will typically be advised to initially take 200 micrograms at the onset of each breakthrough pain flash. The maximum number of pain flashes that can be treated in a 24 hour period is four. Consult with your doctor after taking this medication if you believe that the dosage amount requires adjustment.

Buccal tablets:

Initially, you will likely be prescribed a dosage of 100 micrograms to be taken at the onset of a pain episode. With the advisement and approval of your doctor, this dosage may be repeated after a waiting period 30 minutes. These tablets may be taken to treat up to four episodes in one day or 24 hour period. Consult with your doctor if you require an adjustment to your dosage amount or frequency.

Transmucosal lozenges:

Each pain flash can be treated with 200 micrograms up to four flashes per day. If you require multiple doses, it is recommended that you observe a 15 minute waiting period between them. Speak with your doctor if you do not find the medication to be as effective as you need it to be.

Sublingual spray:

One spray of this medication contains about 100 micrograms, which is the equivalent of a single dose. Repeat doses are possible after 30 minutes ensuing from the first dose, and with your doctor's approval. If the initial two doses are not sufficient, it is necessary to wait at least four hours prior to administering another dose.

Sublingual tablets:

Your doctor will advise you as to the appropriate dosage and frequency for your case, with a 100 microgram tablet being the standard for this delivery method. This medicine can be used to treat up to four pain flashes in one day, and it is recommended that 30 minutes elapse between doses.

The dosage and frequency with which children take fentanyl will be determined by their physician or pediatrician on a case by case basis.

Major Drug Interactions

Fentanyl has been reported to cause negative interactions with some other medications. Be sure to alert your doctor to all of the medications and over the counter drugs that you are taking prior to starting your course of treatment.

While there are some medications that will make fentanyl a less desirable choice for your pain management, your doctor may overcome these concerns by altering the way that you take one or both of these medications. If you are currently taking one of the medicines listed below, be sure that you discuss the implications of taking both of the medications concurrently with your doctor in a thorough manner.

The use of fentanyl may not be worth the risk if you are already taking one of these drugs listed below. Your doctor will advise you on how to proceed:

  • Naltrexone
  • Mifepristone
  • Amifampridine

It is not highly recommended that any of the drugs listed below, however, your doctor may find that proceeding with fentanyl and one of these medications concurrently is the appropriate course of action. If you are taking one of these medications as well as fentanyl, be sure to work closely with your doctor and notify them of any negative reactions that you may experience.

  • Acepromazine
  • Zopiclone
  • Alefacept
  • Zolmitriptan
  • Almotriptan
  • Zaleplon
  • Amiodarone
  • Voriconazole
  • Amitriptyline
  • Verapamil
  • Amoxapine
  • Tryptophan
  • Anileridine
  • Triflupromazine
  • Aripiprazole
  • Trifluoperazine
  • Atazanavir
  • Trazodone
  • Benperidol
  • Tramadol
  • Boceprevir
  • Tolonium Chloride
  • Bromazepam
  • Tilidine
  • Brompheniramine
  • Thioridazine
  • Buspirone
  • Thiopental
  • Butorphanol
  • Temazepam
  • Carbinoxamine
  • Telaprevir
  • Carisoprodol
  • Suvorexant
  • Ceritinib
  • Sulpiride
  • Chlordiazepoxide
  • St. John's Wort
  • Chlorpromazine
  • Siltuximab
  • Ciprofloxacin
  • Sertraline
  • Clarithromycin
  • Selegiline
  • Clonazepam
  • Secobarbital
  • Clozapine
  • Safinamide
  • Cocaine
  • Ritonavir
  • Conivaptan
  • Rifampin
  • Cyclosporine
  • Remoxipride
  • Darunavir
  • Rasagiline
  • Desipramine
  • Ramelteon
  • Dexamethasone
  • Quazepam
  • Dextromethorphan
  • Propofol
  • Diacetylmorphine
  • Promazine
  • Dichloralphenazone
  • Procarbazine
  • Dihydrocodeine
  • Prednisone
  • Diphenhydramine
  • Posaconazole
  • Dolasetron
  • Piritramide
  • Doxepin
  • Piperacetazine
  • Dronedarone
  • Pimavanserin
  • Duloxetine
  • Phenobarbital
  • Eletriptan
  • Perphenazine
  • Enflurane
  • Perazine
  • Erythromycin
  • Pentobarbital
  • Estazolam
  • Pazopanib
  • Ethchlorvynol
  • Pargyline
  • Ethylmorphine
  • Papaveretum
  • Fluconazole
  • Paliperidone
  • Fluoxetine
  • Oxycodone
  • Flurazepam
  • Oxazepam
  • Fluvoxamine
  • Opium Alkaloids
  • Fosaprepitant
  • Olanzapine
  • Fospropofol
  • Nitrous Oxide
  • Furazolidone
  • Nilotinib
  • Granisetron
  • Nicomorphine
  • Haloperidol
  • Nialamide
  • Hydrocodone
  • Nelfinavir
  • Hydroxytryptophan
  • Naratriptan
  • Idelalisib
  • Nafcillin
  • Imatinib
  • Morphine
  • Indinavir
  • Molindone
  • Isocarboxazid
  • Moclobemide
  • Itraconazole
  • Mirtazapine
  • Ketazolam
  • Midazolam
  • Ketoconazole
  • Methylene Blue
  • Levorphanol
  • Meprobamate
  • Methohexital
  • Lithium
  • Methdilazine
  • Lorazepam
  • Metaxalone
  • Lumacaftor
  • Meptazinol
  • Meclizine
  • Melperone
  • Mesoridazine
  • Lurasidone
  • Methadone
  • Lorcaserin
  • Meperidine
  • Methocarbamol
  • Lopinavir
  • Methotrimeprazine
  • Linezolid
  • Mibefradil
  • Levomilnacipran
  • Milnacipran
  • Ketobemidone
  • Mitotane
  • Ketamine
  • Modafinil
  • Isoflurane
  • Moricizine
  • Iproniazid
  • Morphine Sulfate Liposome
  • Imipramine
  • Nalbuphine
  • Iloperidone
  • Nefazodone
  • Hydroxyzine
  • Nevirapine
  • Hydromorphone
  • Nicardipine
  • Halothane
  • Nifedipine
  • Halazepam
  • Nitrazepam
  • Golimumab
  • Nortriptyline
  • Frovatriptan
  • Opium
  • Fosphenytoin
  • Orphenadrine
  • Fosamprenavir
  • Oxcarbazepine
  • Fluspirilene
  • Oxymorphone
  • Fluphenazine
  • Palonosetron
  • Flunitrazepam
  • Paregoric
  • Flibanserin
  • Paroxetine
  • Ethopropazine
  • Pentazocine
  • Eszopiclone
  • Perampanel
  • Escitalopram
  • Periciazine
  • Enzalutamide
  • Phenelzine
  • Eluxadoline
  • Phenytoin
  • Efavirenz
  • Pimozide
  • Droperidol
  • Pipotiazine
  • Doxylamine
  • Pitolisant
  • Donepezil
  • Prazepam
  • Diphenoxylate
  • Primidone
  • Diltiazem
  • Prochlorperazine
  • Difenoxin
  • Promethazine
  • Diazepam
  • Propoxyphene
  • Dezocine
  • Quetiapine
  • Dexmedetomidine
  • Ranolazine
  • Desvenlafaxine
  • Remifentanil
  • Delavirdine
  • Rifabutin
  • Dantrolene
  • Risperidone
  • Cyclobenzaprine
  • Rizatriptan
  • Codeine
  • Saquinavir
  • Cobicistat
  • Secukinumab
  • Clorazepate
  • Sertindole
  • Clobazam
  • Sibutramine
  • Citalopram
  • Sodium Oxybate
  • Chlorzoxazone
  • Sufentanil
  • Chlorpheniramine
  • Sumatriptan
  • Chloral Hydrate
  • Tapentadol
  • Carphenazine
  • Telithromycin
  • Cariprazine
  • Thiethylperazine
  • Carbamazepine
  • Thiopropazate
  • Butabarbital
  • Thiothixene
  • Buprenorphine
  • Tizanidine
  • Bromopride
  • Topiramate
  • Bosentan
  • Tranylcypromine
  • Blinatumomab
  • Triazolam
  • Baclofen
  • Trifluperidol
  • Asenapine
  • Trimeprazine
  • Aprepitant
  • Venlafaxine
  • Amprenavir
  • Vilazodone
  • Amobarbital
  • Vortioxetine
  • Amisulpride
  • Ziprasidone
  • Alprazolam
  • Zolpidem
  • Alfentanil
  • Zotepine

Patients using the two medications listed below concurrently with fentanyl have reported higher incidences of side effects. If you are currently taking one of these drugs and your doctor also prescribes fentanyl, be sure to keep them informed of any negative side effects or symptoms that you experience.

  • Spiramycin
  • Josamycin

There may be certain foods or beverages that should be avoided when taking fentanyl. It is advised that patients inform their physicians of any alcohol or tobacco habits that they may have. It is important to always inform your doctor of any changes in your medications, overall health and wellness and significant alterations to your daily routine. The following substances should be avoided by patients who are currently taking this medication:

  • Grapefruit juice
  • Ethanol

If you suffer from any of the following medical conditions, they may be adversely affected by your use of fentanyl. Your doctor will provide further guidance on how to most effectively navigate the use of this medication while also being treated for:

  • Alcohol abuse
  • Diabetes
  • Bradyarrhythmia (slow heart rhythm)
  • Chronic obstructive pulmonary disease (COPD)
  • Head injury
  • Respiratory problems
  • Brain tumor
  • Kidney disease
  • Drug dependence
  • Liver disease


While taking fentanyl, your doctor will likely order ongoing diagnostic testing, to ensure that there are no significant and negative side effects occurring and to monitor the effectiveness of the medication.

Because fentanyl has been proven to be habit-forming in some instances, it is important that patients only use the prescribed dosage, even if they feel that the drug is losing some of its effectiveness. Consult with the prescribing physician prior to making any changes to the quantity you take and frequency with which you take fentanyl.

Fentanyl is appropriate for use in cancer patients who experience pain bursts that do not respond to typical treatments. Do not use this drug for treatment of headaches or other pains or to treat pain following an injury or surgery.

When using a CNS depressant, such as fentanyl, patients must be aware of the changes that it can cause in their reaction to other CNS depressants, such as alcohol or many over the counter medications. If you are taking fentanyl, be sure to consult with your doctor prior to taking any cough suppressants, allergy medications, cold treatments or similar non-prescription drugs. The use of this medicine with any sleep aids, anesthetics, seizure medications or muscle relaxants is not recommended. Be sure to discuss the situation thoroughly with your doctor prior to taking any of these types of medicines.

Patients may experience drowsiness, confusion or lightheadedness while taking fentanyl. If you are going to engage in any activity that requires full alertness, such as driving or operating machinery, be sure that you understand how your body will react to the fentanyl before you engage in such activity. If these effects, such as dizziness and confusion, begin to interfere with your daily life, confer with your doctor about possible solutions to this situation.

One of the side effects of long-term use of narcotics can be constipation. If you experience this symptom, your doctor may recommend a laxative or advise that you increase your consumption of fiber and drink more liquids. It is important that this situation is dealt with effectively, as prolonged constipation can lead to more serious issues.

Patients have reported withdrawal symptoms when stopping this medication and it should never be discontinued without the advice and supervision of the prescribing physician. Side effects can be minimized by slowly weaning oneself off of the drug, but this endeavor should never be undertaken without the advice of your doctor.

It is possible to overdose on fentanyl, especially as this medication is often used with another narcotic drug. If you experience severe breathing problems, stop breathing or become unconscious, it is imperative that emergency medical care is sought immediately. Discuss the signs and symptoms of overdose with your doctor and primary caregiver and be aware of the necessary steps to take should they occur.

Patients that are taking Actiq need to maintain regular dental care, as this medication contains sugar and has been reported to hasten tooth decay.

If you are taking a monoamine oxidase (MAOI) inhibitor within a two week period, you must refrain from taking fentanyl until your doctor recommends that it is safe to do so.

Be sure to advise your doctor of all medications that you are currently taking, both prescription and non-prescription, prior to starting your fentanyl course of treatment. Some herbal remedies, such as St. John's wort, have caused negative reactions in patients that are taking fentanyl. Also, advise your doctor of any vitamin or mineral supplements that you are taking.


It is always best practice to keep all medications in their original packaging. Do not expose to extreme heat or cold or allow to freeze. Keep in a dry location with low moisture and at room temperature.

Fentanyl can be harmful or even fatal if ingested by pets or children. It is imperative that this medicine is stored out of the reach of children and pets and is disposed of in an appropriate and safe manner.

If, at the conclusion of your course of treatment, you have excess medication or medication that is unused or expired, do not keep it at home. If you are unsure of how to dispose of any unused or expired medication, it is always best to confer with your physician or pharmacist for guidance.

Patients who have been subscribed the Subsys spray version of fentanyl are advised to use a disposal bag that is completely sealed prior to disposal. If you have any unopened spray vials, empty them into the disposal bottle, which is then placed into the disposal bag. Be sure to discard of the sealed disposal bag in a trash container that is out of the reach of both children and pets. If you have any questions or concerns about this process, it is always best to consult with your pharmacist for guidance.


This drug affects the central nervous system (CNS) which can cause certain side effects. Many people avoid narcotics due to the likelihood of addiction that can be both mental and physical. However, patients who suffer from severe pain may need to put those fears aside, as narcotics can be one of the more effective drug options in the treatment of severe pain. If patients do develop a physical dependence on this medication, their medical team can work with them to help minimize the effects of withdrawal. It is important that patients do not stop taking this medication quickly or without medical supervision.

Patients who are experiencing extreme pain may be less likely to develop a psychological dependence on this medication. If you are concerned about the potential for dependency developing while taking this medication, be sure to discuss your concerns with your doctor.

Fentanyl has been reported to cause overdose, so patients taking this medication, and their caregivers, need to be fully aware of the signs and symptoms of overdose and seek immediate emergency attention should they occur.

Patients who are taking fentanyl for the treatment of pain bursts related to their cancer will likely find relief with this drug, but must still be aware of the complications and other reactions that have been reported by patients that have used fentanyl.

Patients are advised to notify their doctors of all of the medications that they are currently taking prior to beginning a course of treatment with fentanyl. This drug can cause a number of side effects and unwanted symptoms and patients who are taking fentanyl should notify their prescribing physicians of any unwanted side effects that occur.