Methadone

What is methadone?

Methadone is a prescription-only man-made opioid used mainly to help people overcome heroin addiction. It is also used for end-of-life care and severe pain and can be used as a cough medicine for end-of-life care. It works like heroin or morphine but in a safer, more controlled way[1].  

If you're addicted to heroin and want to stop, visit the NHS website for more information. 

What is methadone used to treat?

TMethadone is commonly used for[1]: 

• Heroin addiction – it helps reduce cravings and withdrawal symptoms 

• Severe pain – especially when other painkillers no longer work, in palliative care 

How does methadone work?

Methadone binds to the same brain receptors as heroin and morphine, but[1]: 

• It doesn’t cause the same intense ‘high’ 

• It lasts much longer, helping to stabilise the body 

• It prevents withdrawal symptoms (like shaking, sweating, anxiety) 

Who can take methadone?

Methadone is suitable for[1]: 

• Adults aged 18 and over with opioid addiction 

• Newborns (in hospital only) if exposed to opioids in the womb 

Speak to your doctor if you have[1]: 

• An allergy to methadone 

• Serious breathing, heart, liver, thyroid, adrenal, or kidney problems (unless carefully monitored) 

• A head injury or bad headaches 

• Ever abused or been dependent on alcohol, prescription medication, or illegal drugs 

• Ulcerative colitis 

• Low blood pressure 

• Myasthenia gravis 

• Are pregnant, trying to get pregnant, or are breastfeeding 

Please tell your doctor or pharmacist about any conditions you may have or medication you take before you start treatment, and always follow the instructions in the Patient Information Leaflet[2].  

What is a typical dose of methadone?

The dose is tailored to each person by a specialist. You’ll usually start on 10mg to 30mg, taken once a day, which can be increased slowly until your withdrawal symptoms and cravings stop. Many people take a regular dose of between 60mg to 120mg daily, however your dose may be different depending on[1]: 

• The amount of heroin you’re using 

• If you’re using alcohol or drugs 

• A urine or saliva sample 

• Your physical and mental health 

• If you’ve had drug treatment before 

If it’s just being used for pain, the usual dose is 2.5ng to 10mg every 8 to 12 hours. 

How do you take methadone?

Methadone is usually[1]: 

• Taken as a green liquid, once daily 

• Often given under supervision at a pharmacy (especially at the start) 

• For pain, it may come as tablets or injections 

Can you stop taking methadone?

Yes – but never stop suddenly[1]. 

• Stopping too fast can lead to severe withdrawal symptoms 

• Your doctor will help you slowly reduce the dose if you plan to stop 

What if you take too much methadone?

Overdose is dangerous – call 999 immediately. Signs of overdose include[1]: 

• Very slow or shallow breathing 

• Extreme sleepiness or drowsiness 

• Cold, clammy skin 

• Slow heartbeat 

• Unconsciousness 

What if you forget to take methadone?

IIf you miss a dose of methadone, take it as soon as you remember. If your next dose is soon, skip the previous dose and never double up. If you miss more than 3 days, your dose may need to be restarted at a lower level, so you should contact your doctor or pharmacist[1]. 

Medicines you can and can’t take with methadone

Use caution or avoid[1]: 

• Alcohol – raises the risk of overdose or serious side effects 

• Benzodiazepines (e.g. diazepam) – is a common cause of fatal overdose. 

• Other opioids – increases overdose risk 

• Some antidepressants and antipsychotics – may affect heart rhythm 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of methadone?

The most common side effects include[1]: 

• Constipation 

• Nausea 

• Sweating 

• Drowsiness 

The rare, but more serious side effects include[1]: 

• Breathing problems 

• Serious heart rhythm risks (QT prolongation) 

• Severe allergic reaction (rash, swelling, trouble breathing) 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

Symptoms of anaphylaxis include:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about methadone

Is methadone addictive? 
Yes – but it’s used in a controlled way to help people come off more dangerous opioids safely[1].  

Can I drink alcohol while taking methadone? 
Avoid it. Combining methadone with alcohol can be very dangerous[1]. 

Can I drive on methadone? 
You must inform the DVLA if taking methadone long-term. Driving while impaired is illegal. [1]. 

Can I take methadone while pregnant? 
Only under specialist care and it may cause neonatal withdrawal. It’s generally avoided for people breastfeeding as methadone concentrates in milk, causing infant drowsiness/breathing issues[1]. 

Do I need to avoid any food or drink while taking methadone? 
Yes, avoid drinking grapefruit juice or eating grapefruit as it can make side effects worse[1]. 

For the official NHS guide for methadone, visit their website.