Fentanyl is prescribed to treat severe pain.
The most common side-effects are feeling sick, constipation, and feeling sleepy. If you start to feel extremely sleepy or your breathing becomes slow or shallow, you should contact your doctor straightaway.
Fentanyl is likely to affect your reactions and ability to drive. It may be an offence to drive while affected. Do not drive until you know how you react.
|Type of medicine||A strong opioid painkiller (analgesic)|
|Used for||Pain relief|
|Also called||Brands of fentanyl patches: Durogesic DTrans®; Fencino®; Fentalis®; Matrifen®; Mezolar®; Mylafent®; Opiodur®; Osmanil®; Tilofyl®; Victanyl®
Brand of fentanyl lozenges: Actiq®
Brands of fentanyl sublingual tablets: Abstral®; Recivit®
Brand of fentanyl buccal tablets: Effentora®
Brand of fentanyl buccal film: Breakyl®
Brands of fentanyl nasal sprays: Instanyl®; PecFent®
|Available as||Patch, lozenge, tablets and film to dissolve in the mouth (buccal), tablets to dissolve under the tongue (sublingual), nasal spray, injection|
Fentanyl is an opioid medicine (sometimes called an opiate). It is a strong painkiller. It works by binding to certain tiny areas, called opioid receptors, in your brain and spinal cord (central nervous system). This leads to a decrease in the way you feel pain and your reaction to pain.
If you have pain which is ongoing (chronic), it is likely you will be prescribed a patch containing fentanyl to apply to your skin. This is often called transdermal fentanyl. Patches contain fentanyl in a reservoir and release it gradually over a period of time to give you continual pain relief. Despite this, there may be times when your pain is not fully controlled and you experience breakthrough pain. Fentanyl is also useful for this type of pain, but different formulations are used, such as lozenges, tablets, films or nasal sprays. These fentanyl preparations are taken as necessary to ease breakthrough or severe pain.
Fentanyl is also given by injection to ease pain during surgical operations.
Before using fentanyl
Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking fentanyl, it is important that your doctor knows:
- If you are pregnant or breast-feeding.
- If you have a problem with the way your liver works, or a problem with the way your kidneys work.
- If you have a sore mouth or diabetes. This is because some brands of fentanyl may not be suitable for you to take.
- If you have prostate problems or any difficulties passing urine.
- If you have any breathing problems, such as asthma or chronic obstructive pulmonary disease (COPD).
- If you have been told you have low blood pressure.
- If you have any problems with your thyroid or adrenal glands.
- If you have epilepsy.
- If you have a problem with your bile duct.
- If you have been constipated for more than a week or have an inflammatory bowel problem.
- If you have a condition causing muscle weakness, called myasthenia gravis.
- If you have recently had a severe head injury, or have a brain tumour.
- If you have ever been dependent on drugs or alcohol.
- If you have ever had an allergic reaction to a medicine.
- If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
How to use fentanyl
- Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about fentanyl and will provide you with a step-by-step guide on how to use the product you have been supplied with. It will also give you a full list of the side-effects which you may experience from having fentanyl.
- Take fentanyl exactly as your doctor tells you to. There are several different preparations available, so your doctor or pharmacist will tell you how you should take your doses. When you first start taking fentanyl, your doctor will gradually increase your dose to make sure that you have the dose that eases your pain but minimises any unwanted symptoms. Once you have been told what dose is right for you, keep taking this dose unless you are told otherwise by your doctor.
- Your dose will be on the label of the pack. Make sure you follow the instructions your doctor has given you carefully. If you are unsure either about your dose or how to use the fentanyl preparation you have been given, ask your pharmacist to explain this to you again.
If you are using fentanyl patches
- Open the protective pouch carefully and remove the patch. Check that the patch has not been damaged in any way as you have opened the pouch. (Keep the opened pouch to use later to dispose of the patch once it has been used.)
- Place the patch on a dry, non-hairy, healthy area of skin on your upper arm or upper body. Press it firmly on to your skin for approximately 30 seconds to make sure that it sticks well, especially around the edges. It is important that you avoid touching the sticky side of the patch while you do this. After you've applied the patch, wash your hands to make sure you have no fentanyl on your fingers.
- When you first use a patch, it may take up to 24 hours for the patch to reach its full effect; so, during this time, you may need alternative pain relief. Your doctor will explain this to you.
- Leave the patch in place for 72 hours (three days), then remove it and apply a new patch to a different area of skin on your upper arm or body. Remember to change the patch at the same time of day every three days.
- Fold the removed patch in half with the sticky side inwards and put it back into a protective pouch. Dispose of the pouch as you have been directed by your doctor, making sure it is safely out of the reach of any children.
- Try to make sure that any patch you are wearing does not come into contact with a heat source such as a heating pad, hot water bottle, electric blanket, or a heated water bed. Heated items like these can increase the amount of fentanyl that is released from the patch, which increases the risk of overdose. Having long hot baths, saunas, or sunbathing are also best avoided.
- Let your doctor know if you develop a high temperature at any time, as this also can increase the amount of fentanyl you absorb from the patch.
- Each time you collect your prescription, check to make sure you have been given the same brand of fentanyl patches as you have had before. This is because different brands may release different amounts of fentanyl and you should keep to the same brand unless your doctor has advised you otherwise.
- Signs of having too much fentanyl include shallow or weak breathing, feeling very sleepy or confused, slurred speech and extreme dizziness. If you have any of these effects, remove the patch and contact your doctor straightaway.
If you are using fentanyl lozenges (Actiq®)
- These lozenges have an applicator attached so that you can move the lozenge around inside your mouth as you suck. Move the applicator around so that the lozenge comes into contact as much as possible with your tongue and the inside of your cheeks. Be careful not to chew or swallow the lozenge. As the lozenge dissolves, fentanyl will be absorbed through the lining of your mouth. If your mouth is dry, it may help to moisten your mouth with a drink of water before you suck the lozenge.
- Suck one lozenge over a period of about 15 minutes. If your pain has not eased within 15 minutes after having finished this lozenge, suck another lozenge. Do not use more than two lozenges for any episode of pain, or more than four lozenges in any 24-hour period. If your pain is not controlled by this, you must let your doctor know.
If you are using fentanyl sublingual tablets (Abstral® or Recivit®)
- Place the tablet under your tongue and allow it to dissolve completely. Do not chew, suck or swallow the tablet. You can moisten your mouth with a drink of water before placing the tablet under your tongue, but do not eat or drink anything while the tablet is dissolving.
- If your pain has not eased within 15-30 minutes, you may use another tablet. Do not use more than two tablets for any episode of pain. If your pain is not controlled by this, you must let your doctor know. If you have another episode of breakthrough pain, it is important that you leave at least two hours after treating the first episode before you treat the further episode. If you are having more than four episodes of breakthrough pain in any 24-hour period, you should let your doctor know about this.
If you are using fentanyl buccal tablets (Effontora®)
- Place the tablet between your gum and cheek and allow it to dissolve completely. Do not chew, suck or swallow the tablet. You can moisten your mouth with a drink of water before placing the tablet in your mouth, but do not eat or drink anything while the tablet is dissolving. However, if after 30 minutes there are still bits of tablet remaining in your mouth, you can swallow these with a drink of water.
- If your pain has not eased within 30 minutes, you may use another tablet but use this on the other side of your mouth or, alternatively, place it under your tongue. Do not use more than two tablets for any episode of pain. If your pain is not controlled by this, you must let your doctor know. If you have another episode of breakthrough pain, it is important that you leave at least four hours after treating the first episode before you treat the further episode.
If you are using fentanyl buccal film (Breakyl®)
- Moisten your mouth with a drink of water and then place the film between your gum and cheek, with the pink side facing your cheek. Hold it in place for a few seconds until it sticks. Leave it for 15-30 minutes to allow it to dissolve completely. Do not drink anything for 5 minutes after inserting the film, and do not eat anything while the film is dissolving.
- If you have another episode of breakthrough pain, it is important that you leave at least four hours after treating the first episode before you treat the further episode. If your pain is not controlled by this, you must let your doctor know.
If you are using fentanyl nasal spray (Instanyl® or PecFent®)
- Use one spray into one of your nostrils. It is best if you sit or stand while you use the spray. Hold the spray upright and bend your head slightly forward. Close one nostril by placing a finger against it and insert the tip of the spray into the other nostril. Press the spray once while you are breathing in through your nose.
- If your pain has not eased within 10 minutes, use a second spray into the other nostril. Do not use more than two sprays for any episode of pain and do not use the spray again within four hours. If your pain is not controlled by this, you must let your doctor know. Likewise, if you are having more than four episodes of breakthrough pain in any 24-hour period, you should let your doctor know about this too.
Getting the most from your treatment
- You should not drink alcohol while you are taking fentanyl. This is because fentanyl will increase the risk that you experience side-effects from the alcohol, such as feeling dizzy and sleepy.
- You will not be given fentanyl for longer than is necessary. If you take opioid painkillers over a longer period of time, your body can become used to them and they will not work as well. This is called tolerance. Also, opioid painkillers repeatedly taken over a period of time can cause withdrawal symptoms when the treatment is then stopped. If you no longer need fentanyl, your doctor will want you to reduce your dose gradually before you stop taking it. This will help to prevent any unpleasant effects.
- If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking an opioid painkiller.
- If you buy any medicines, check with a pharmacist that they are safe to take with fentanyl.
- If you are planning a trip abroad you are advised to carry a letter with you from your doctor because fentanyl is a controlled drug. If you plan to travel for more than three months, you must check with the Home Office before you travel, as you will need to apply in writing for a licence to take fentanyl with you.
Can fentanyl cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with fentanyl. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.
|Common fentanyl side-effects
||What can I do if I experience this?|
|Constipation||Try to eat a well-balanced diet and drink plenty of water each day. If this continues your doctor may prescribe a laxative for you|
|Feeling or being sick||This usually passes after a few days, but let your doctor know if it continues. Your doctor may prescribe a medicine to ease the sickness|
|Feeling sleepy, tired or dizzy||Do not drive or use tools or machines. Do not drink alcohol|
|Breathing problems||If your breathing becomes slow or shallow, you should contact your doctor straightaway|
|Dry or sore mouth, diarrhoea, indigestion, tummy pain (may be caused by spasm of the bile ducts), mood changes, headache, sweating, itchy skin rash||Speak with your doctor if troublesome|
|Local irritation where a patch or tablet has been||As much as possible, vary the sites where the patches or tablets are placed. If this becomes a problem, let your doctor know|
If you experience other symptoms which you think may be due to fentanyl, speak with your doctor or pharmacist for further advice.
How to store fentanyl
- Keep all medicines out of the reach and sight of children. This includes used patches and part-finished lozenges.
- Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Further reading & references
- British National Formulary; 68th Edition (Sep 2014) British Medical Association and Royal Pharmaceutical Society of Great Britain, London
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr John Cox