Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content


8-minute read

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 an 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.
  • If you take fentanyl and your pain is not well controlled, or you have any unexpected side effects, see your doctor.
  • Fentanyl is available in several formulations in different strengths.
  • 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 pain caused by major trauma or surgery, as well as 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 works directly on opioid receptors in the central nervous system and reduces feelings of pain by interrupting the way nerves signal pain between the brain and the body.

It is available in several formulations in different strengths, including patches, lozenges, tablets that disintegrate in your mouth and sublingual (under the tongue) tablets. Fentanyl is also given by injection for severe acute 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 these 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, so 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:

Always take medicines exactly as your doctor prescribes, and as directed by your pharmacist.

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.

Your doctor will monitor how you use fentanyl to reduce your risk of harm, including through misuse or abuse.

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.

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

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

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

If your kidney or liver function is impaired, your doctor may decide that fentanyl is not appropriate for you. There are also other factors that may limit your use of fentanyl — for example, if you drink alcohol or take other medicines that can cause drowsiness.

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.

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.

If you have chronic (long-term) pain, your doctor might suggest lifestyle changes to help manage the discomfort. These might include physical fitness and activity pacing, social activities, relaxation techniques and overall health management.

You can find more information here 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 side effects, see your doctor. 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' since this can lead to 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 since this is dangerous to others and harmful to the environment.

Resources and support

Asking about your treatment or medication is important to help you understand your options. Here's a guide to questions to ask your pharmacist or doctor before taking a medicine.

See also 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 telephone 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: January 2021

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Fentanyl - Alcohol and Drug Foundation

Fentanyl is part of a group of drugs known as opioids. Opioids interact with opioid receptors in the brain and elicit a range of responses within the body; from feelings of pain relief, to relaxation, pleasure and contentment.

Read more on Alcohol and Drug Foundation website

Accidental fentanyl exposure in children can be fatal - NPS MedicineWise

Children are at higher risk of accidental exposure to fentanyl, a potent opioid that treats pain. Fentanyl patches are particularly dangerous. Read more.

Read more on NPS MedicineWise website

Fentanyl: next wave of the opioid crisis - Alcohol and Drug Foundation

Details about the fentanyl crisis in Canada were shared with the ADF in a recent tour here by Canadian drug policy reform advocate Senator Larry Campbell.

Read more on Alcohol and Drug Foundation website

Opioids | SA Health

Information on opioids for clincians, includes treatment options as well as opioid misuse

Read more on SA Health website

Fentanyl Side Effects, Overdose and Withdrawal | Your Room

Fentanyl is a prescription drug which can come with many short and long term side effects. Find out what to do in the case of overdose or withdrawal.

Read more on NSW Health website

Opioids - Alcohol and Drug Foundation

Opioids include any drug that acts on opioid receptors in the brain, and any natural or synthetic drugs that are derived from or related to the opium poppy.

Read more on Alcohol and Drug Foundation website

Prescription opioids Effects and FAQs | Your Room

Opioids are natural drugs derived from the opium poppy or synthetic drugs, and have a depressant or sedating effect, causing the brain and central nervous system to slow down.

Read more on NSW Health website

Opioid (pain reliever) infusion | Sydney Children's Hospitals Network

When children have strong pain due to surgery, injury or illness, they need constant pain relief

Read more on Sydney Children's Hospitals Network website

Adverse events associated with medium‐ and long‐term use of opioids for chronic non‐cancer pain: an overview of Cochrane Reviews - Els, C - 2017 | Cochrane Library

Read more on Cochrane (Australasian Centre) website

Cancer pain -

Cancer pain doesn’t affect all people with cancer, but for those who do have pain it can be controlled with medicines and other therapies. 

Read more on myDr website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.