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Fentanyl facts

What is fentanyl?

Effects of fentanyl


Further information


Please note: The information given on this page is not medical advice and should not be relied on in this way. Individuals wanting medical advice on this issue should consult a health professional.

What is fentanyl?

Fentanyl is a depressant drug, which means it slows down the messages travelling between the brain and body. It belongs to a group of drugs known as 'opioids' that are from the opium poppy. It is prescribed for the control of chronic, severe pain as a result of cancer, nerve damage, back injury, major trauma or other causes.1 In Australia, Fentanyl is a schedule 8 drug.2 It is about 80 to 100 times stronger than morphine3.

Fentanyl comes in a number of different forms and strengths including:

  • Transdermal patches (Durogesic® and generic versions)
  • Lozenges/lollipops (Actiq®)
  • IV injection (Sublimaze®)2

How is it used?

The transdermal patch is applied to the skin and provides strong and consistent pain relief at an even rate over a 72 hour period.1 The patch is the most commonly used form of fentanyl.

The lozenges are dissolved in the mouth and are used for breakthrough pain in patients already taking regular opiates for severe pain.1

The IV solution is injected for pain relief and sedation during minor surgery and it's duration of action is short.1

Some people use fentanyl illegally to become intoxicated by extracting the fentanyl from the patch and injecting it. This is very risky as there is little difference between the amount needed to get 'high' and the amount that causes overdose. It is also extremely hard to judge a 'correct' dose size.

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 patches)

The following effects may be experienced:

  • 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

More severe

  • Chest pain
  • Slowed breathing
  • Bluish lips and complexion
  • Seizure
  • Passing out
  • Coma
  • Death1,4


Naloxone (also known as Narcan®) reverses the effects of opiates (including fentanyl), in the case of an overdose. Naloxone can be injected intravenously (into a vein) or intramuscularly (into a muscle) by medical professionals, such as paramedics. It can also be administered by family and friends of people who use opiates. Speak with your chemist or pharmacist for more information.

Naloxone information video

Injecting fentanyl and sharing needles may also cause:

  • Tetanus
  • Hepatitis B
  • Hepatitis C
  • HIV/AIDs

Long term effects

Regular use of fentanyl may cause:

  • Mood instability
  • Reduced libido
  • Constipation
  • Menstrual problems
  • Respiratory impairment3

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
  • Depression3

Information about withdrawal

Further information

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.4,5


Reducing the risks



1. Upfal, J. (2006). The Australian drug guide (7th ed.). Melbourne: Black Inc.

2. NPS Medicinewise (n.d.). Fentanyl.

3. Brands B; Sproule B; & Marshman J. (Eds.) (1998) Drugs & Drug Abuse (3rd Ed.) Ontario: Addiction Research Foundation.

4. Medline Plus. (2014). Fentanyl Transdermal Patch.

5. NPS Medicinewise. (2015). Accidental fentanyl exposure in children can be fatal.


Last updated: 8 June 2016

Information you heard is intended as a general guide only. This audio is copyrighted by the Australian Drug Foundation. Visit for more