How does fentanyl work?
Fentanyl binds to opioid receptors in the brain and spinal cord, blocking pain signals and producing pain relief. It also slows breathing and can create a feeling of relaxation.
What is fentanyl used to treat?
Fentanyl is typically prescribed for:
- Severe chronic pain (such as cancer pain)
- Post-surgical pain
- Pain relief for people who cannot take other opioids
Who can take fentanyl?
Fentanyl is prescribed for adults and sometimes children with severe pain that requires strong, long-acting medication. It is not usually prescribed for mild or short-term pain.
Who might not be able to take fentanyl?
Fentanyl may not be suitable if you:
- Have breathing difficulties (e.g., severe asthma or COPD)
- Have a history of substance misuse or opioid addiction
- Have low blood pressure or severe liver disease
- Are not already taking regular opioid pain relief
Can I take fentanyl if I’m pregnant or breastfeeding?
Fentanyl isn’t usually recommended during pregnancy or while breastfeeding, as it can affect the baby. If you are pregnant, planning a pregnancy, or breastfeeding, speak to your doctor about alternative pain relief.
What if I miss a dose?
If you forget to take a dose of fentanyl, do not double up—speak to your doctor for advice. If using a fentanyl patch, replace it as soon as you remember and adjust your schedule accordingly.
How effective is fentanyl?
Fentanyl is highly effective for severe pain relief but must be used exactly as prescribed to avoid serious side effects, including overdose.
What should I do if I take too much?
Fentanyl overdose is extremely dangerous and can cause:
- Severe drowsiness or unconsciousness
- Slow or stopped breathing
- Cold, clammy skin
If you think you’ve taken too much, seek emergency medical help immediately.
What dose of fentanyl is usually taken?
Doses vary depending on the condition being treated and the type of fentanyl used:
- Patches: Applied every 72 hours
- Lozenges/tablets: Taken as needed for breakthrough pain
- Injections: Given in hospitals for severe pain
Powered by pharmacies
With over 1,700 pharmacy partners across the UK, you can get the help you need, wherever you are based.
Our website and mobile app make it easy and convenient to manage your health needs and book services at a pharmacy nearby.
What are the side effects of fentanyl?
Common side effects include:
- Drowsiness
- Nausea or vomiting
- Constipation
- Dizziness
- Sweating
Serious side effects, such as breathing difficulties, confusion, or loss of consciousness, require urgent medical attention.
How should I take fentanyl?
Fentanyl must be taken exactly as prescribed. Patches should be applied to clean, dry skin, and tablets or lozenges should be used only as directed.
When should fentanyl be taken?
Fentanyl is taken as prescribed—either at set intervals (patches) or when needed for pain relief (tablets/lozenges). Never take more than prescribed.
What are the brand names for fentanyl?
Fentanyl is available under different brand names, including:
- Durogesic
- Actiq
- Fencino
Final thoughts
Fentanyl is a powerful painkiller that should only be used under strict medical supervision. Misuse can lead to serious side effects, dependence, or overdose. If you have concerns about its use or side effects, speak to your doctor or pharmacist immediately.
