Methadone for pain

This information is intended for use ONLY after you have been prescribed methadone for pain.

Key points about methadone

  • Methadone is used for the relief of moderate to severe pain, for example pain caused by a terminal illness such as cancer.
  • Methadone liquid is also called Biodone.
  • Find out how to take it safely and possible side effects.
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Methadone is used for the relief of moderate to severe pain, for example pain caused by a terminal illness such as cancer. Methadone belongs to a group of medicines called opioids and is usually used when other opioids, such as morphine or oxycodone, don’t work well enough. Read more about painpain-relief medication and opioid painkillers.

Note: Methadone is also used to manage substance misuse. The way methadone is used in substance misuse is different from the way methadone is prescribed for pain management.

  • In Aotearoa New Zealand, methadone is available as an injection, tablets and as a liquid.
  • The dose of methadone is different for different people. 
  • Depending on your pain, your doctor may advise that you take regular doses or take methadone only when you need it for pain relief. Make sure you know which is right for you.
  • Always take your methadone exactly as your doctor has told you. Do not change the dose yourself.
  • If you think that it's no longer working, let your doctor know.
  • The pharmacy label on your medicine will tell you how much to take, how often to take it and any special instructions.

  • You can take methadone with or without food.
  • Tablets: Swallow the tablets with a glass of water. 
  • Liquid: Measure the liquid carefully with an oral syringe or measuring spoon. You can get these from your pharmacy. Do not use a kitchen spoon as it won't give you the right amount. Methadone liquid comes in different strengths. Always read the label carefully. The pharmacy label on your medicine will tell you how much methadone to take, how often to take it and any special instructions.
  • Missed dose: If you're taking it regularly and you forget to take your dose, take it as soon as you remember that day. But if it's nearly time for your next dose, just take the next dose at the right time. Don't take double the amount.

Here are some things to know when you're taking methadone. Other things may be important as well, so ask your healthcare provider what you should know about.


Eat plenty of fibre and drink more water while you are taking methadone

  • Methadone can affect your bowel movements – it might be hard or painful to poo (constipation).
  • If this happens, ask your healthcare provider for a laxative to soften your poo.
  • Eating foods with fibre, drinking plenty of water and keeping active can help.


Methadone can make you sleepy, drowsy, dizzy or affect your concentration

  • If you’re drowsy or sleepy, don’t take your next dose until you’re wide awake. Ask your healthcare provider for advice.
  • Limit or avoid alcohol as it can make these effects worse.
  • Don’t drive a vehicle, ride a bike or operate machinery (including power tools) and don’t make important personal or business decisions or sign legal papers if you are feeling sleepy, drowsy or have trouble concentrating.


Taking other medicines

  • Your doctor may recommend taking other pain relievers such as paracetamol and NSAIDs (ibuprofen, diclofenac, naproxen) as well. If taken regularly, they can reduce how much methadone you need to take.
  • If you're taking any other medicines, or starting a new medicine, check with your doctor or pharmacist to make sure they're safe to take with methadone. This includes any medicines you buy without a prescription (over the counter), such as herbal and complementary medicines or recreational drugs.


Methadone reduces severe pain but won’t take all of your pain away

If your pain isn’t improving don’t take extra doses. You can also try other ways to manage your pain such as relaxation techniques, gentle exercises and stretches.

Like all medicines, methadone can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Feeling sleepy, dizzy or tired
  • Vertigo
  • Problems with concentration
  • These are common when starting methadone or after increasing the dose.
  • Be careful when driving or using tools until you know how this medicine affects you.
  • Do not drink alcohol.
  • Feeling sick (nausea) or being sick (vomiting)
  • This is common when you first start taking methadone.
  • Mostly this settles and goes away.
  • Tell your doctor if this bothers you.
  • You may need an anti-sickness tablet at times.
  • Constipation
  • Constipation is very common and can be quite severe.
  • Ask your doctor to prescribe a suitable laxative, which you need to take regularly. 
  • You also need to eat more fibre (such as fruit, vegetables, brown bread and bran-based breakfast cereals) and drink plenty of water. 
  • Read more about how to ease and prevent constipation.
  • Headache, dry mouth, changes in your eyesight or vision
  • Flushing or sweating
  • Tell your doctor if they bother you.
  • Mood changes, sleep problems, hallucinations, confusion, nightmares
  • Palpitations or feeling like your heart is racing
  • Tell your doctor if they bother you.
  • Changes in breathing (slow or shallow), hard to wake up, seizures
  • Difficulty urinating (passing pee)
  • Tell your doctor immediately or phone Healthline 0800 611 116.
  • Signs of an allergic reaction, such as skin rashes, itches, swelling of your face, lips or mouth, or difficulty breathing  
  • Tell your doctor immediately or phone Healthline 0800 611 116.

Read more about medicines and side effects and reporting a reaction you think might be a side effect.

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5 questions to ask about your medications

5 questions to ask about your medications

Health Quality and Safety Commission, NZ, 2019 English, te reo Māori

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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