What is methadone?
Methadone is an opioid medication. An opioid is sometimes called a narcotic. Methadone reduces withdrawal symptoms in people addicted to heroin or other narcotic drugs without causing the “high” associated with the drug addiction.
Methadone is used as a pain reliever and as part of drug addiction detoxification and maintenance programs and is only available from certified pharmacies.
You should not use methadone if you have severe asthma or breathing problems, or a bowel obstruction called paralytic ileus.
Methadone can slow or stop your breathing, especially when you start using this medicine or whenever your dose is changed. Never use this medicine in larger amounts, or for longer than prescribed. This medicine may be habit-forming, even at regular doses. Never share this medicine with another person, especially someone with a history of drug abuse or addiction. Keep the medication in a place where others cannot get to it.
MISUSE OF NARCOTIC MEDICATION CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription.
Methadone may cause a life-threatening heart rhythm disorder. Call your doctor at once if you have a headache with chest pain and severe dizziness, and fast or pounding heartbeats.
Methadone is available only from a certified pharmacy.
Before using methadone
You should not use methadone if you are allergic to it, or if you have:
- severe asthma or breathing problems; or
- a bowel obstruction called paralytic ileus.
Methadone may cause a life-threatening heart rhythm disorder. Your heart function may need to be checked during treatment.
Some medicines can interact with methadone and cause a serious condition called serotonin syndrome. Be sure your doctor knows if you also take medicine for depression, mental illness, Parkinson’s disease, migraine headaches, serious infections, or prevention of nausea and vomiting. Ask your doctor before making any changes in how or when you take your medications.
To make sure this medicine is safe for you, tell your doctor if you have:
- heart disease, a heart rhythm disorder, or a personal or family history of long QT syndrome;
- an electrolyte imbalance (such as low levels of potassium or magnesium in your blood);
- any type of breathing problem or lung disease;
- a history of head injury, brain tumor, or seizures;
- a history of drug abuse, alcohol addiction, or mental illness;
- liver or kidney disease;
- urination problems; or
- problems with your gallbladder, pancreas, or thyroid.
It is not known whether methadone will harm an unborn baby. If you use this medicine while you are pregnant, your baby could become dependent on the drug. This can cause life-threatening withdrawal symptoms in the baby after it is born. Babies born dependent on habit-forming medicine may need medical treatment for several weeks. Tell your doctor if you are pregnant or plan to become pregnant.
Methadone can pass into breast milk and may cause breathing problems or addiction and withdrawal symptoms in a nursing baby. Tell your doctor if you are breast-feeding a baby.
How should I use methadone?
Methadone may be habit-forming, even at regular doses. Never share this medicine with another person, especially someone with a history of drug abuse or addiction. MISUSE OF NARCOTIC MEDICATION CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription. Selling or giving away methadone is against the law.
Follow all directions on your prescription label. Methadone can slow or stop your breathing, especially when you start using this medicine or whenever your dose is changed. Never use in larger amounts, or for longer than prescribed. Tell your doctor if the medicine seems to stop working as well in relieving your pain.
Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
Dissolve the dispersible tablet in at least 4 ounces of water, orange juice, or other citrus-flavored non-alcoholic beverage. Allow the tablet to disperse in the liquid. The tablet will not dissolve completely. Drink this mixture right away. To get the entire dose, add a little more water to the same glass, swirl gently and drink right away.
Never use methadone tablets or liquid to make a mixture for injecting the drug into your vein. This practice has resulted in death with the misuse of methadone and similar prescription drugs.
When used as part of a treatment program for drug addiction or detoxification, your doctor may recommend that each dose be given to you by a family member or other caregiver.
Additional forms of counseling and/or monitoring may be recommended during treatment with methadone.
You should not stop using this medicine suddenly. Follow your doctor’s instructions about tapering your dose.
Store at room temperature away from moisture and heat. Keep the medication in a place where others cannot get to it.
Keep track of how much of this medicine has been used. Methadone is a drug of abuse and you should be aware if any person in the household is using this medicine improperly or without a prescription.
Do not keep leftover methadone pills or liquid. Ask your pharmacist where to locate a drug take-back disposal program. If there is no take-back program, flush any unused pills or liquid medicine down the toilet. Disposal of medicines by flushing is recommended to reduce the danger of accidental overdose causing death. This advice applies to a very small number of medicines only. The FDA, working with the manufacturer, has determined this method to be the most appropriate route of disposal and presents the least risk to human safety.
What happens if I miss a dose?
If you take methadone for pain: Take the missed dose as soon as you remember, then take your next dose 8 to 12 hours later. Skip the missed dose if it is almost time for your next scheduled dose.
If you take methadone for drug addiction: Take your missed dose the next day at the regular time. If you miss your doses for longer than 3 days in a row, call your doctor for instructions. You may need to restart at a lower dose.
Do not use extra medicine to make up a missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. A methadone overdose can be fatal, especially in a child or other person using the medicine without a prescription. Overdose symptoms may include slow breathing and heart rate, severe drowsiness, muscle weakness, cold and clammy skin, pinpoint pupils, and fainting.
What should I avoid?
Do not drink alcohol. Dangerous side effects or death can occur when alcohol is combined with methadone. Check your food and medicine labels to be sure these products do not contain alcohol.
Methadone may impair your thinking or reactions. Avoid driving or operating machinery until you know how this medicine will affect you. Dizziness or severe drowsiness can cause falls or other accidents.
Grapefruit and grapefruit juice may interact with methadone and lead to unwanted side effects. Discuss the use of grapefruit products with your doctor.
Methadone side effects
Get emergency medical help if you have any signs of an allergic reaction to methadone: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Even if you have used other narcotic medicines, you may still have serious side effects from methadone.
Call your doctor at once if you have:
- weak or shallow breathing;
- severe constipation;
- a light-headed feeling, like you might pass out;
- infertility, missed menstrual periods;
- impotence, sexual problems, loss of interest in sex;
- symptoms of a life-threatening heart rhythm disorder – a headache with chest pain and severe dizziness, and fast or pounding heartbeats; or
- low cortisol levels – nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.
Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.
Methadone is more likely to cause breathing problems in older adults and people who are severely ill, malnourished, or otherwise debilitated.
Common methadone side effects may include:
- dizziness, drowsiness;
- nausea, vomiting; or
- increased sweating.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.