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If a person is not breathing, or if they are unresponsive, seek help straight away. Call triple zero (000) and ask for an ambulance.

Key facts

  • Fentanyl is a strong opioid pain medicine that can only be prescribed by your doctor.
  • Fentanyl is prescribed for severe pain, when other pain medicines have been ineffective or cannot be used.
  • Fentanyl is available in several formulations in different strengths.
  • If you take fentanyl and your pain is not well-controlled, or you have any unexpected side effects, see your doctor.
  • Always take fentanyl exactly as your doctor prescribed.

What is fentanyl?

Fentanyl is a strong opioid medicine that can be prescribed by your doctor as part of a broader strategy to help manage your pain.

LOOKING FOR A MEDICINE? — See this list of medicines that contain fentanyl to find out more about a specific medication.

What is fentanyl used for?

Fentanyl is used to treat acute (short term), severe pain caused by major trauma or surgery, as well as for chronic pain caused by cancer.

How long you need to take fentanyl for will depend on why it has been prescribed. For example, fentanyl patches for cancer pain or in people receiving palliative care are approved for life-long use, while fentanyl used in acute pain or anaesthesia will be used only for a short time.

How does fentanyl work?

Fentanyl reduces feelings of pain by interrupting the way nerves signal pain between the brain and the body. It works directly on the central nervous system.

What forms of fentanyl are there?

Fentanyl is available in several formulations in different strengths, including:

  • patches to stick on your skin
  • lozenges
  • tablets that disintegrate in your mouth
  • sublingual (under the tongue) tablets
  • a spray applied inside your nose

Fentanyl is also given by injection for acute, severe pain or as part of anaesthesia before surgery.

What are the possible side effects of taking fentanyl?

All opioids, including fentanyl, can have side effects, including life-threatening breathing problems. The risk of side effects is higher:

  • when first taking fentanyl
  • after a dosage increase
  • if you are older
  • if you have an existing lung problem

Fentanyl affects everyone differently. If you have any of these side effects while taking fentanyl, or if you notice anything that is making you feel unwell, speak with your pharmacist or doctor.

The side effects of fentanyl are similar to those of other opioids, and include:

It is important to follow the directions given to you by your doctor or pharmacist when taking this medicine.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

What are the risks associated with fentanyl?

Opioids are strong pain medicines and can cause life-threatening or fatal breathing difficulties.

Fentanyl may make it difficult for you to drive or operate heavy machinery. If you have recently started taking an opioid medicine or changed dosage, you may be at a higher risk of having an accident.

WORRIED ABOUT YOUR OPIOID USE? — The Opioid Risk Indicator can help you find out if you may be developing a problem.

If your kidney or liver function is impaired, your doctor may decide that fentanyl is not right for you. Fentanyl is not suitable for some people, for example, if you drink alcohol or take other medicines that can cause drowsiness.

Never take an opioid medicine that was prescribed for someone else, or give another person an opioid that was prescribed for you. Your doctor is the best person to guide you on whether fentanyl is the right medicine for you, how much you need and how long to take it for.

Opioid dependence

If you take fentanyl, you may become dependent on this medicine even if you take it exactly as prescribed by your doctor. Your doctor will monitor how you use fentanyl, to reduce your risk of harm, including through misuse, abuse and addiction.

You can also develop tolerance when you take fentanyl. This means that you may need to take larger amounts of the opioid to get the same effect. As the dosage increases, so does the risk of side effects.

Continue to take fentanyl for as long as your doctor tells you to. Suddenly stopping fentanyl can cause withdrawal symptoms.

If a person is not breathing, or if they are unresponsive, seek help straight away. Call triple zero (000) and ask for an ambulance.

Access to overdose-reversing medication

Naloxone is a medicine that can temporarily reverse the effects of an opioid overdose. The Australian Government is offering this medication free of charge and without a prescription to people who may experience, or witness, an opioid overdose.

Learn more about the Take Home Naloxone program.

Are there any alternatives to fentanyl?

Different pain relief medicines are used in different circumstances. If you have been prescribed fentanyl and are still in pain, speak with your doctor about other ways you can manage your pain.

Always check with your doctor or pharmacist before making any change to the dosage or type of medicine you take.

If you have chronic (long-term) pain, your doctor might suggest lifestyle changes to help manage the effects of pain. This may include:

Find out more about options for managing chronic pain.

When should I see my doctor?

If your pain is not well controlled on fentanyl or you have any unexpected or unwanted side effects, see your doctor. There are different options for pain management, and your doctor can suggest other approaches.

Do not adjust your fentanyl dosage without talking to your doctor first.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Pain Question Planner to prepare for your doctor’s appointment.

How do I dispose of medicines safely?

It's important you dispose of unwanted opioid medicines safely. Unused medicines can be returned to any pharmacy. Don't keep unused medicines 'just in case', as this can lead to dangerous or inappropriate use.

Dispose of a used fentanyl patch by folding it over on itself (bringing the adhesive sides together).

Keep fentanyl out of reach of children and pets. Never throw medicines into a garbage bin or flush them down the toilet, as this is dangerous to others and harmful to the environment.

Resources and support

Asking about your treatment or medicine is important to help you understand your options.

Here's a guide to questions you should ask your pharmacist or doctor before taking any medicine.

See this list of medicines that contain fentanyl to read the consumer medicine information (CMI) leaflet for the brand prescribed, or:

  • Call 1300 MEDICINE (1300 633 424) to talk about the medicines you are taking for your pain.
  • Discuss your pain on the Pain Link helpline (1300 340 357) which is staffed by volunteers with personal experience of chronic pain.
  • Got to Painaustralia to find pain services and programs in your area.
  • Learn more about prescription opioids on the Choosing Wisely website.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: May 2023

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