Fentanyl

How is fentanyl used?

Pharmaceutical fentanyl can be taken in many different ways, including via nose (nasal spray), mouth (pills or tablets that dissolve in your mouth), injection and skin (patches).⁶

While there are patches specifically formulated for absorbing fentanyl through the skin, other forms can’t be used this way and you won’t experience the effects or overdose just by touching them.⁸

Illegally made fentanyl can be swallowed, injected, smoked or snorted.²

Effects of fentanyl

The use of any drug can have risks. It’s important to be careful when taking any type of drug.

Fentanyl can affect 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 and from batch to batch for illegally made fentanyl).

Onset and duration of effects

How fast a drug takes effect and how long it lasts can vary depending on how it's taken - for example, whether it's snorted, swallowed, or injected.⁹

• If snorted or absorbed under the tongue: effects felt in 15 - 30 minutes and can last 1 - 4 hours.
• Skin patches: effects felt in 2 - 4 hours and can last 48 - 72 hours.¹⁰

Effects

Effects can include:

• pleasure, feelings of happiness (euphoria)
• pain relief
• upset stomach, nausea, vomiting
• constipation or diarrhoea
• wind, indigestion, cramps
• drowsiness, confusion
• weakness or fatigue
• headache
• incoherent or slurred speech
• dizziness, impaired balance
• slow pulse, lowered blood pressure
• rash (inflammation, itch, swelling) from the skin patch. ^{5, 11, 12}

If injecting drugs, there is an increased risk of:

• tetanus
• infection
• vein damage.¹³

If sharing needles, there is an increased risk of:

• hepatitis B
• hepatitis C
• HIV and AIDS.¹³

Impact of mood and environment

Drugs that affect a person’s mental state (psychoactive drugs) can also have varied effects depending on a person’s mood (often called the ‘set’) or the environment they are in (the ‘setting’):

• Set: a person’s state of mind, previous encounters with the drug, and expectations of what’s going to happen. For example, feelings of stress or anxiety before using fentanyl may result in an unpleasant experience and make those feelings worse.
• Setting: the physical and social environment where you take fentanyl – whether it’s known and familiar, who you're with, if you're indoors or outdoors, the type of music or sounds, and lighting. The ideal setting to take fentanyl will vary based on the individual and drug they’re using.¹⁴

Being in a good state of mind, with trusted friends and a safe environment before taking fentanyl reduces the risk of having a bad experience.¹⁴

Overdose

If you take a large amount of fentanyl or use a strong batch, you could overdose.

Your risk of overdose can also increase if you mix fentanyl with alcohol or other drugs, including medications.

Fentanyl overdose can cause death.¹⁵

Call triple zero (000) and request an ambulance if you or someone else has any of the following symptoms (emergency services are there to help and can provide more instructions).

Signs of opioid overdose can include:

• unconscious or non-responsive
• slow breathing, abnormal breathing, or not breathing at all
• slow or no heartbeat and pulse
• choking or gurgling sounds
• skin colour changes, especially lips and fingernails
• bluish-purple skin for people with lighter complexions
• greyish or ashen skin for people with darker complexions
• vomiting
• cool or clammy (wet and sweaty) skin
• small ‘pinpoint’ pupils.^{12, 16}

Learn more on overdose and drug-related emergencies.

Naloxone

Naloxone (also known as Nyxoid®/Narcan®) temporarily reverses the effects of opioid overdose (including fentanyl). It’s available for free over the counter from most local pharmacies and can be administered by anyone, including family or friends and bystanders.¹⁷

If a person does not respond to the first dose after 3 minutes, give them a second dose. This can be repeated until the ambulance arrives.^{18, 19}

Mixing with other drugs

Mixing fentanyl with other drugs can have unpredictable effects and increase the risk of harm.

Mixing includes using more than one drug (including alcohol or medications) at the same time, or one after another. You should also consider what drugs you’ve taken in the last 24 hours.

• Fentanyl and GHB/GBL/benzodiazepines/alcohol: can cause difficulty breathing, passing out, vomiting and possible death.
• Fentanyl and cannabis: can work together to increase the effects of both drugs, so there is a risk of being more impaired than wanted or planned.
• Fentanyl and cocaine/ice/speed: increases the risk of heart strain. The stimulant effect of cocaine increases heart rate, while the opioids decrease heart rate. There is a risk of breathing or heart problems if one drug wears off before the other.
• Fentanyl and ketamine: can cause nausea, vomiting, passing out and possible death.
• Fentanyl and anti-depressants: there have been rare reports of a risk of serotonin syndrome when using SSRIs. There have also been rare reports of severe and varied reactions from MAOIs.
• Fentanyl and nitrous oxide: can cause impaired coordination, memory loss and passing out.^{10, 20}

Using more than one drug or type of drug at the same time is called polydrug use.¹²

Reducing harm

• If prescribed, follow the directions given to you by your doctor or pharmacist. Don’t stop using your medicine or lower the dose without checking with your doctor.
• Don’t take fentanyl with other opioids or depressants, this increases the risk of overdose.
• Always carry naloxone and encourage family and friends to also carry it.
• Avoid driving or operating machinery after using.
• Fentanyl patches should be stored out of reach of children, at room temperature, and away from excess heat and moisture (not in the bathroom). To dispose of used patches, fold inwards on itself, so the sticky sides meet, wrap in plastic or paper and put in the rubbish.
• If injecting, use new needles and sterile injecting equipment to avoid blood-borne viruses.
• Fentanyl may unknowingly be in - or be sold as - other drugs, such as cocaine or MDMA
• use in a safe place with people you trust and who can help, if needed
• ‘start low, go slow’ - try a small amount first and wait a while to see how you are affected
• use drug checking (pill testing) services, where available - if there is no drug checking service near you, your local needle and syringe program (NSP) may have fentanyl test strips
• check for drug alerts related to the drug you are taking.^{2, 20-22}

Coming down

Fentanyl is not known to cause comedown effects.

Long-term effects

Long-term effects can vary depending on how much, how often and how fentanyl is consumed. Regular use may eventually contribute to:

• dependence
• less effective pain relief (tolerance)
• increased risk of getting sick from viruses and infections
• sleep problems
• reduced bone density and higher risk of breaking bones
• heightened sensitivity to pain (opioid-induced hyperalgesia)
• impacts on hormone levels leading to reduced sex drive, infertility, erectile dysfunction, or menstrual cycle changes.^{21, 23, 24}

Fentanyl and mental health

It’s common for people using illicit opioids to experience mental health problems at some point in their lives. This doesn’t mean that using opioids causes mental health problems. For some people, fentanyl is used to help them cope with symptoms of mental ill-health.

In some cases, the side effects of long-term fentanyl use (like sleep difficulties) can lead to people developing mental health issues.¹²

More than half of those who use illicit opioids report experiencing symptoms of a mental illness at some point in their lives, most commonly depressive and anxiety disorders. More than 40% of people who use illicit opioids experience symptoms of PTSD.¹²

Up to half of people who use illicit opioids have experienced childhood trauma.¹²

Tolerance

Regularly taking fentanyl can lead to developing a tolerance, which means you need to take larger amounts to get the same effects.¹⁵

Tolerance to fentanyl also affects other opioids (known as cross-tolerance). For example, tolerance to fentanyl will also result in a higher tolerance to oxycodone or heroin.^{25, 26}

Tolerance should return to normal within 1 – 2 weeks of not using opioids.²⁶

People taking opioid medications long term may be switched by their doctor to a different opioid to reduce the amount of medication they need to take. This is known as opioid rotation.²⁵

Dependence

People who regularly use fentanyl may become dependent. They may feel they need to use fentanyl to go about usual activities like working, studying and socialising, or just to get through the day.¹⁵

Withdrawal

Withdrawal refers to the symptoms that can occur when someone who is dependent on a drug, or who has been using it regularly over time, stops or reduces their use.²⁷

Withdrawal can include physical symptoms (such as headaches, or nausea) and psychological symptoms (such as anxiety, or depressed mood).²⁷

Symptoms - including how strong they are and how long they last - will vary depending on the type of drug and a person’s history of use.²⁷

Withdrawal from fentanyl can be potentially life-threatening.²⁸

Seek advice from a health professional before stopping fentanyl as they can help you slowly reduce your dose (taper), or access opioid pharmacotherapy. This can help reduce withdrawal symptoms or prevent them from occurring.

Withdrawal symptoms

Reducing, or stopping using fentanyl after a period of regular use can lead to withdrawal symptoms, including:

• 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
• diarrhoea
• increased heart rate and blood pressure
• pains in the bones and muscle
• general weakness
• depression.^{11, 27}

Withdrawal symptoms usually start within 12 hours after the last dose and can last for about a week. Days one to three will be the worst.^{11, 27}

Reduced tolerance and overdose risk

After withdrawing from opioids such as fentanyl, your body is no longer used to it and your tolerance drops.²⁶

This means if you use the same amount as before, it can be too much for your body and cause an overdose.²⁶

Always start with a lower dose after a break from fentanyl or other opioid drugs.²⁶

Pregnancy and breastfeeding

Before pregnancy

There is research that shows opioid drugs, including fentanyl, can impact fertility.

Opioids can:

• affect menstrual cycles
• lower sex drive.
• lower testosterone levels
• reduce sperm quality and movement
• cause erectile dysfunction.^29-31

During pregnancy

Opioid use during pregnancy can harm the baby’s development.^{32, 33}

Opioids can pass to your baby via the placenta. This can affect the baby’s growth and result in a premature (early) birth, which has other health impacts on the baby.^{32, 40}

Other chemicals may be present in illegal or counterfeit (fake) opioid medication, and there is no way to know exactly how these will impact the baby or the pregnancy.²

If you’re injecting opioids, it’s important to not share injecting equipment with other people. This protects you and the baby from bloodborne viruses such as HIV and hepatitis C.³⁴

After pregnancy

Opioid use during pregnancy can sometimes cause withdrawal symptoms in babies after birth. This is known as neonatal opioid withdrawal syndrome (NOWS).^{33, 35}

NOWS is easily diagnosed and treated, and not all babies will experience symptoms.³⁵

Breastfeeding your baby while using opioids in high doses is not recommended, as the drugs can be present in breastmilk and affect the baby.^{32, 36, 37}

If you’re planning to breastfeed, make sure you talk with your midwife or doctor about your use of opioids.³³

Getting help

If your use of fentanyl is affecting your health, family, relationships, work, school, financial or other life situations, or you’re concerned about someone, there is help and support.

• Call the National Alcohol and Other Drug Hotline on 1800 250 015 for free and confidential advice, information and counselling about alcohol and other drugs.
• Search our Help and Support directory to find your preferred support, by adding your location or postcode and filtering by service type.