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Methadone Injection BP
Methadone Hydrochloride BP 10mg/ml
Keep this leaflet. You may need to read it again.
If you have any further questions, ask your doctor or pharmacist.
This medicine has been prescribed for you. Do not pass it on to others. It may harm
them, even if their symptoms are the same as yours.
If any of the side effects gets serious, or if you notice any side effects not listed in this
leaflet, please tell your doctor or pharmacist.
In this leaflet:
1. What Methadone Injection is and what it is used for
2. Before you are given Methadone Injection
3. How Methadone Injection is given to you
4. Possible side effects
5. How to store Methadone Injection
6. Further information
Methadone is a type of medicine called an opioid analgesic. The word opioid means a
substance similar to opium, for instance strong pain relievers such as morphine or codeine.
An analgesic is a medicine that can be used to relieve pain.
Methadone Injection is used to relieve moderate to severe pain, or in the treatment of
addiction to opioid drugs (eg. morphine and heroin) when it can control the withdrawal
symptoms that occur when these drugs are stopped.
You should not be given this medicine if:
• You know that you are allergic to methadone or one of the other ingredients in this product (listed at the
end of this leaflet).
• You have any problems that affect your breathing including chronic bronchitis or emphysema.
• You have had a head injury.
• You suffer from alcoholism.
• You have a problem of paralysis of the gut.
• You suffer from tumour of the adrenal gland (situated near the kidney).

• You are taking monoamine oxidase inhibitors (MAOIs) or have been taking them within the last two
weeks. MAOIs (eg. phenelzine or isocarboxazid) are medicines used to treat depression.
• You are a child under 16 years of age.
Speak to your doctor if one of these applies to you before you are given this medicine.
Take special care and tell your doctor if:
• You had an asthma attack just before you are given this medicine.
• Your blood pressure is abnormally low, or you have an underactive thyroid gland (which may cause
tiredness, intolerance to cold, constipation, and puffiness of the face).
• You have an enlarged prostate gland causing difficulty in passing water.
• You have a condition that makes you have fits, eg. epilepsy.
• You have a problem with your liver or kidneys or adrenal gland.
• You suffer from obstructive bowel disorders or biliary tract disorders.
• You suffer from myasthenia gravis (muscle weakness).
• You are in shock (life-threatening condition that occurs when the body is not getting enough blood flow)
• You are pregnant or breast-feeding.
• You are an elderly patient.
• You have any kind of heart disease (eg. abnormalities of heart rate or rhythm, heart blocks, inadequate
blood supply to heart).
• You have a blood relative who has died suddenly
• You have been told that you have low levels of potassium or magnesium in your blood.
In certain cases, your doctor may need to monitor your heart with an electrocardiogram (ECG) before
starting or during treatment with methadone.
Speak to your doctor if one of these applies to you before you are given this medicine.
Taking other medicines
Tell your doctor before you are given this medicine if you are taking or have recently taken any other
medicines, including medicines obtained without a prescription.
A large number of drugs can interact with Methadone which can significantly alter their effects.
These drugs include:

• Medicines for depression (eg tricyclic antidepressants such as amitriptyline, desipramine,
fluvoxamine, fluoxetine) and medicines for anxiety (eg benzodiazepines such as diazepam)
• Medicines for schizophrenia or other serious mental illness, such as phenothiazines (which may be
present in various medicines including some for treating allergic disorders, nausea (feeling sick) and
vomiting (being sick))
• Sedatives, sleeping tablets or barbiturates (eg. phenobarbital for epilepsy)
• Phenytoin, carbamazepine and primidone (for epilepsy)
• Antibiotics for infection (eg. erythromycin, rifampicin and ciprofloxacin), and certain antifungal
medicines (eg. ketoconazole and similar drugs)
• Drugs used to treat HIV infection such as ritonavir, nevirapine or zidovudine
• Cimetidine (for heartburn or peptic ulcer)
• Naloxone (which reverses the effects of methadone and other opioid medicines)
• Pethidine (used for pain relief)
• St. John's wort (herbal preparation)
• Drugs which are likely to effect conduction of impulses to the heart (eg. drugs for irregular
heartbeats) or salts and chemicals (electrolytes) in your blood (eg. Water tablets).
If you are already taking one of these medicines, speak to your doctor before you receive Methadone
Taking Methadone Injection with food and drink
You must tell your doctor if you drank a lot of alcohol within 24 hours before you are given Methadone
Injection, or are planning to drink a lot of alcohol after you have been given this injection. You must
avoid drinking alcohol whilst taking Methadone Injection as it may increase the risk of developing
breathing problems and low blood pressure.
Pregnancy and breast-feeding
Tell your doctor before you are given this medicine if you are pregnant, think you may be pregnant or are
planning to become pregnant, or are breast-feeding.
There is no evidence of harmful effects in pregnancy. You should not be given Methadone Injection if
you are in labour or if you are breast-feeding.
Driving and using machines
Methadone can cause drowsiness and clouding of consciousness which could interfere with your ability to
use machines. Do not operate machinery whilst you are taking this medicine. When your methadone
treatment has stopped, ask your doctor when it will be safe for you to drive or use machines.
The medicine can affect your ability to drive as it may make you sleepy or dizzy.

Do not drive while taking this medicine until you know how it affects you.
It is an offence to drive if this medicine affects your ability to drive.
However, you would not be committing an offence if:
o The medicine has been prescribed to treat a medical or dental problem and
o You have taken it according to the instructions given by the prescriber or in the
information provided with the medicine and
o It was not affecting your ability to drive safely

Talk to your doctor or pharmacist if you are not sure whether it is safe for you to drive while taking this
Tolerance and dependence
Methadone can become less effective with repeated use. This is called tolerance and it means that the
dose may have to be increased for methadone to remain effective. If methadone is used repeatedly, it
becomes habit-forming. This is called dependence and if methadone treatment is suddenly stopped,
unpleasant withdrawal symptoms may occur.
Important information about some of the ingredients of Methadone Injection
This medicine contains less than 1mmol sodium (23mg) per dose, i.e. is essentially 'sodium-free'.
Methadone Injection may be administered by injection into a muscle or into the tissue beneath the skin.
• Adults
Use as an analgesic to relieve moderate to severe pain:
The usual single dose is 5 to 10mg. This may be repeated every 6 to 8 hours as required.
Your doctor will adjust the dose to meet your need for pain relief. The dosage and frequency of repeated
doses may be reduced if you are very ill.
Use to treat addiction to opioid drugs:
The usual starting dose is 10 to 20mg per day. This may be increased until there are no signs of
withdrawal and no signs of unwanted effects of the methadone. After this, your doctor will aim to
gradually reduce the dosage.
• Children:
This medicine is not for use in children under 16 years.
• Elderly:
If you are elderly, your doctor may decide to reduce any repeated doses, or to give them
less frequently.
If you have any further questions on the use of this product, ask your doctor or pharmacist.
If you think you have been given more Methadone Injection than you should have or
you think you have missed a dose
Tell your doctor, nurse or pharmacist immediately.

Like all medicines, Methadone Injection can sometimes cause side-effects, although not everyone gets
All medicines can cause allergic reactions although serious allergic reactions are rare. Any sudden
wheeziness, difficulty in breathing, swelling of the eyelids, face or lips, rash or itching (especially
affecting your whole body) should be reported to a doctor immediately.
Other side effects may include:
• dizziness, nausea (feeling sick), vomiting (being sick) or constipation
• headache
• feeling faint especially after standing up
• pain, irritation (such as redness or pain) hardening of the tissue in and around the site of your injection
• menstrual irregularities
• drowsiness, confusion, restlessness
• eye disorders
• dry eyes and nose
• fall in body temperature
• difficulty in passing water
• dry mouth, sweating
• a very slow or rapid or irregular heartbeat
• mood changes, hallucinations (seeing or hearing things that are not there), or a
decreased sex drive
• a skin rash
• respiratory depression (decrease in respiratory rate)
• galactorrhea (spontaneous flow of milk from the breast)
• flushing
If any of the side effects gets serious, or if you notice any side effects not listed in this
leaflet, please tell your doctor or pharmacist.
Keep out of the reach and sight of children.
The product should not be used after the expiry date printed on the ampoule or carton.
Methadone Injection should be protected from light and stored below 25°C.
If only part of the contents of an ampoule is used, the remaining solution should be
The active substance is Methadone hydrochloride BP.
The other ingredients are sodium chloride BP and sodium hydroxide BP (as a 10% w/v
solution) or dilute hydrochloric acid BP in water for injections BP.
What Methadone Injection looks like and contents of pack
Methadone Injection is a clear, colourless, sterile solution. Each 1ml of solution contains
10mg of Methadone hydrochloride.

The solution is presented in clear glass ampoules (bottles), containing either 1ml, 2ml, 5ml
or 10ml. The ampoules are then packed in cardboard cartons with either 5 or 10 ampoules
per box.
Marketing authorization holder
Mercury Pharma International Ltd., 4045, Kingswood Road, City West Business Park, Co Dublin, Ireland
Mercury Pharma International Ltd., 4045, Kingswood Road, City West Business Park, Co Dublin, Ireland
This leaflet was last revised in April 2014

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Source: Medicines and Healthcare Products Regulatory Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.