Last published: December 14, 2020

What is fentanyl?

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.

It is prescribed in the event of chronic, severe pain as a result of cancer, nerve damage, back injury, major trauma and surgery.1 In Australia, fentanyl is a schedule 8 drug.2 It is about 80 to 100 times stronger than morphine.3

What it looks like

Fentanyl is available in many forms. Pharmaceutical fentanyl is used for managing acute or chronic pain. Illicit fentanyl can be manufactured for use in the illegal drug market.

Medicinal use

Medicinal fentanyl comes in a number of different forms and strengths including:

  • transdermal patches (Durogesic®, APO-fentanyl® and generic versions)
  • lozenges/lollipops (Actiq®)
  • intravenous injection (Sublimaze® B. BRAUN FENTANYL®).

Illicit use

Some people use fentanyl illegally by extracting the fentanyl from the patch and injecting it. This is very risky as it is extremely hard to judge a dose size.

Fentanyl can be ‘diverted’. Diversion occurs when medication that is prescribed by a medical professional, is not used as directed, or is given or sold to a third party.

Prescribed fentanyl can be 'diverted' when:

  • individuals obtain medication without a prescription from another doctor through their profession (e.g. healthcare professionals)
  • individuals use their own prescribed medication recreationally
  • individuals use medication prescribed to another person.

Fentanyl is sometimes mixed with other drugs to increase potency. Illicitly manufactured fentanyl can be:

  • a stand alone product
  • a low cost additive to increase the potency of other illicit drugs such as heroin
  • sold as counterfeit medicines (such as oxycodone®).

Effects of fentanyl

There is no safe level of drug use. Use of any drug always carries some risk. It’s important to be careful when taking any type of drug.

Fentanyl affects everyone differently, based on:

  • size, weight and health
  • whether the person is used to taking it
  • whether other drugs are taken around the same time
  • the amount taken
  • the strength of the drug (varies between drug form e.g. patches, lozenges or injection)

Fentanyl affects everyone differently, but effects may include:

  • euphoria
  • relief from pain
  • nausea, vomiting
  • constipation and/or diarrohea
  • reduced appetite
  • wind, indigestion, cramps
  • drowsiness, confusion
  • weakness or fatigue
  • dizziness
  • euphoria
  • headache
  • incoherent or slurred speech
  • impaired balance
  • slow pulse and lowered blood pressure
  • rash (inflammation, itch, swelling at patch site). 1, 4


If the dose is too high, you might overdose. Call an ambulance straight away by dialling triple zero (000) if you have any of these symptoms (ambulance officers do not have to involve the police):

  • chest pain
  • slowed breathing
  • bluish lips and complexion
  • seizure
  • passing out
  • coma
  • death.1,5

Naloxone (also known as Narcan®) reverses the effects of opiates (including fentanyl), in the case of an overdose. Naloxone is available as a fast-acting nasal spray and a preloaded multiple dose syringe. They are both available by prescription and are PBS listed. It can be administered by health professionals as well as family or household members and peers.6 Speak with your chemist or pharmacist for more information.

If injecting drugs there is an increased risk of:

  • tetanus.
  • infection.
  • vein damage.

If sharing needles there is an increased risk of:

  • hepatitis B.
  • hepatitis C.
  • HIV and AIDS.

Long term effects

Regular use of fentanyl may cause:

  • mood instability
  • reduced libido
  • constipation
  • menstrual problems
  • respiratory impairment.3

Using fentanyl with other drugs

The effects of taking fentanyl with other drugs – including over-the-counter or prescribed medications – can be unpredictable and dangerous and could cause:

Fentanyl + alcohol: adds to adverse effects and may increase the risk of respiratory depression.

Fentanyl + MAOI anti-depressants: may result in severe unpredictable reactions.

Fentanyl + benzodiazepines: may add to the sedative effects and diminished breathing.1


Giving up fentanyl after using it for a long time is challenging because the body has to get used to functioning without it. Withdrawal symptoms usually start within 12 hours after the last dose and can last for about a week, days 1 to 3 will be the worst. These symptoms can include:

  • goose flesh/bumps
  • bouts of chills alternating with bouts of flushing and excessive sweating
  • irritability
  • insomnia
  • loss of appetite
  • yawning and sneezing
  • watery eyes and runny nose
  • vomiting and nausea
  • diarrohea
  • increased heart rate and blood pressure
  • pains in the bones and muscle
  • general weakness
  • depression.3

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In Australia between 2000-2011, one hundred and thirty-six fentanyl-related deaths were recorded.

54% had a history of injecting drug use and 95% had injected fentanyl at the time of death.

Deaths were primarily among Australians aged under 47 years.7

Safe storage and disposal

Fentanyl patches should be stored at room temperature, away from excess heat and moisture (not in the bathroom). To dispose of used fentanyl patches fold the patch inwards on itself so that the adhesive sides meet, and return to the dispensing pharmacy. Wash your hands well with soap and water after disposing of the fentanyl patches. Do not put leftover or used fentanyl patches in the rubbish.2,8

  1. Upfal J. The Australian drug guide. 7th ed. Melbourne Black Inc.; 2006.
  2. NPS MedicineWise. Fentanyl Sandoz.: NPS MedicineWise; 2020. [Accessed 27 November 2020]
  3. Brands B, Sproule B, & Marshman J. Drugs & Drug Abuse. 3rd ed. Ontario: Addiction Research Foundation; 1998.
  4. Darke S, Lappin, J, & Farrell, M. The Clinician's Guide to Illicit Drugs. United Kingdom: Silverback Publishing 2019.
  5. Medline Plus. Fentanyl Transdermal Patch: U.S. Department of Health and Human Services; 2020 [Accessed 27 November 2020].
  6. NPS MedicineWise. Naloxone nasal spray (Nyxoid) for opioid overdose: NPS MedicineWise; 2020. [Accessed 27 November 2020].
  7. Roxburgh A Burns L Drummer O Pilgrim J Farrell M & Degenhardt L. Trends in fentanyl prescriptions and fentanyl‐related mortality in Australia. Drug and alcohol review. 2013;32(3):269-75.
  8. NPS MedicineWise. Accidental fentanyl exposure in children can be fatal: NPS MedicineWise; 2015.

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constipation, cramps, diarrhoea, dizziness, euphoria, fatigue, headache, impaired balance, indigestion, low blood pressure, nausea, rash, reduced appetite, relief from pain, skin rashes, slurred speech, treat severe pain, vomiting, weakness, wind