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Methadone oral solution

Metharose, Physeptone

This medicine is an opioid painkiller. There is a serious risk of addiction when taking this medicine, especially if used long-term. The Medicines and Healthcare products Regulatory Agency (MHRA) has issued new guidance for people prescribed an opioid painkiller. If you have any questions or concerns about taking opioids safely please speak with your doctor or a pharmacist.

Methadone oral solution is a substitute for street drugs like heroin which cause dependence and addiction.

It is important for you to continue to take methadone regularly, every day.

You are more likely to succeed in staying off heroin if you have support. Please ask about what counselling and help are available in your area.

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About methadone

Type of medicine

An opioid substitution therapy

Used for

To help manage opioid dependence and addiction in adults (such as heroin addiction)

Also called

Metharose®, Physeptone®

Available as

Oral solution, tablets

Methadone is prescribed to help you keep off street drugs such as heroin. It can help to prevent the unpleasant withdrawal symptoms which can occur when you stop using drugs like these. It is taken by mouth as an oral liquid and it works as a substitution treatment. Many people choose to stay on methadone long-term, although some people gradually reduce their dose and come off it.

The effects of methadone last longer than heroin so it is usually prescribed as a once-daily dose. To begin with, you will usually be asked to take it under the supervision of the person who dispenses the methadone to you. This means there can be no doubt about how much methadone you take at each dose. This supervision may be relaxed after a few months of you taking a regular maintenance dose.

Methadone also acts as a painkiller. It is occasionally used to treat severe pain if other strong painkillers are unsuitable. If you have been prescribed methadone for this reason then you should speak with your doctor or home-care team if you have any questions about your treatment. This document gives information about methadone when it is used to manage drug addiction only.

Before taking methadone

To make sure that this is the right treatment for you, before you start taking methadone it is important that your doctor or pharmacist knows:

  • If you are pregnant or breastfeeding.

  • If you have prostate problems or any difficulties passing urine.

  • If you have any breathing problems, such as asthma or chronic obstructive pulmonary disease (COPD).

  • If you have been told you have low blood pressure or an unusual heart rhythm.

  • If you have any problems with your thyroid or adrenal glands.

  • If you have fits or epilepsy.

  • If you have a problem with the way your liver works or a problem with the way your kidneys work.

  • If you have a problem with your bile duct.

  • If you have been constipated for more than a week or have an inflammatory bowel problem.

  • If you have a condition causing muscle weakness, called myasthenia gravis.

  • If you have recently had a severe head injury.

  • If you have ever had an allergic reaction to a medicine.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

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How to take methadone

  • Carefully follow the advice your doctor has given to you and read any printed information you have been given. The manufacturer's printed information leaflet (which will be supplied with the medicine) will give you more information about methadone and will provide you with a full list of the side-effects which you could experience from taking it.

  • Take methadone exactly as your doctor tells you to. Do not take more, or less, than the dose you have been prescribed. It is usually prescribed as a once-daily dose

  • Try to take your dose at the same time of day, each day. Initially you will be asked to take methadone where you can be supervised. This is to help you stick with your treatment and make sure you do not miss any doses.

  • At first your doctor will prescribe a low-ish dose and then see you frequently to adjust this to a regular maintenance dose. This early stage is very important because too high a dose can cause you serious harm, so please be patient. It may take a few weeks until the correct dose is found and you may have some minor withdrawal symptoms during this time. The correct dose varies from person to person, depending on how much heroin you were using and how your body deals with (metabolises) methadone.

  • If you miss a dose, wait until it is time for your next dose and take this next dose when it is due. Do not take two doses together to make up for a missed dose. It is important that you tell your doctor you have missed a dose. If you miss more than three days of methadone, your dose will need to be changed.

Getting the most from your treatment

  • It is important that you keep your regular appointments with your doctor/clinic so that your progress can be reviewed. You will be asked to give a urine sample from time to time.

  • You are more likely to succeed in staying off heroin if you have support and counselling. Local drug community teams, self-help groups and other agencies can be of help. It is much harder to 'do it alone', so go for counselling and help if it is available in your area.

  • Methadone causes drowsiness and will affect your ability to drive. It is against the law to drive if your driving ability is impaired by this medicine. Even if your driving is not impaired, you will be guilty of an offence unless the methadone has been prescribed for a medical reason and it has been taken according to the instructions given by the prescriber.

  • Do not take more than the dose your doctor has prescribed for you. Signs of overdose can include pinpoint pupils, shallow breathing and, eventually, unconsciousness. If you suspect that you or someone else might have had an overdose of methadone, contact a doctor or go to the accident and emergency department of a local hospital straightaway. Take the container with you, even if it is empty.

  • You should not take any street drugs or drink alcohol while you are on methadone. This is because other street drugs and/or alcohol can increase the risk of overdose and side-effects.

  • Methadone (even in small amounts) is a special hazard to children and other people if it is swallowed by accident. If you suspect that someone else has swallowed some methadone, please get medical help straightaway.

  • Do not stop taking methadone without discussing this with your doctor or drug-team worker first. It is important that methadone should be taken regularly to reduce the risk of withdrawal symptoms from occurring. Withdrawal symptoms from methadone are similar to those from heroin (they are less severe but last longer). When you are ready to consider becoming drug-free, your doctor or drug-team worker will be able to help you decide on the best way to do this in order to keep withdrawal effects to a minimum.

  • If you buy any medicines, please check with a pharmacist that they are safe to take with methadone.

  • If you are having an operation or dental treatment, please tell the person carrying out the treatment that you are taking methadone. It could interfere with an anaesthetic, if needed.

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Can methadone cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with methadone. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common methadone side-effects

What can I do if I experience this?

Feeling sick (nausea) or being sick (vomiting), tummy (abdominal) pain

Stick to simple meals - avoid rich or spicy foods


Eat a well-balanced diet and drink plenty of water each day

Feeling dizzy, faint or sleepy

Do not drive and do not use tools or machines. Do not drink alcohol

Dry mouth

Try chewing sugar-free gum or sucking sugar-free sweets

Other effects include: difficulty passing urine, mood changes, flushing, hypothermia, slow heartbeat, dry eyes and feeling restless

If any of these become particularly troublesome, speak with your doctor

If you experience any other symptoms which you think may be due to methadone, please speak with your doctor, clinic or pharmacist for further advice.

How to store methadone

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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