Methadone may cause slowed breathing and irregular heartbeat, which may be life-threatening. If you experience any of the following symptoms, call your doctor immediately: difficulty breathing; extreme drowsiness; slow, shallow breathing; fast, slow, pounding, or irregular heartbeat; faintness; severe dizziness; or confusion.
The risk that you will experience serious or life-threatening side effects of methadone is greatest when you first start taking methadone, when you switch from another narcotic medication to methadone and when your doctor increases your dose of methadone. Your doctor may start you on a low dose of methadone and gradually increase your dose. Your doctor will monitor you closely during this time.
Follow the directions on your prescription label carefully and ask your doctor or pharmacist to explain any part you do not understand. Take methadone exactly as directed. Do not take more methadone or take methadone more often than prescribed by your doctor. If you are taking methadone to control pain, your pain may return before it is time for your next dose of methadone. If this happens, do not take an extra dose of methadone. You will still have methadone in your body after the pain relieving effect of the medication wears off. If you take extra doses, you may have too much methadone in your body and you may experience life-threatening side effects. Be aware that the pain relieving effects of methadone will last longer as your treatment continues for a longer time. Talk to your doctor if your pain is not controlled during your treatment with methadone.
Talk to your doctor about the risks of taking methadone for your condition.
Use of methadone to treat opiate addiction:
If you have been addicted to an opiate (narcotic drug such as heroin), and you are taking methadone to help you stop taking or continue not taking the drug, you must enroll in a treatment program. The treatment program must be approved by the state and federal governments and must treat patients according to specific federal laws. You may have to take your medication at the treatment program facility under the supervision of the program staff. Ask your doctor or the treatment program staff if you have any questions about enrolling in the program or taking or getting your medication.
Methadone is used to relieve moderate to severe pain that has not been relieved by non-narcotic pain relievers. It also is used to prevent withdrawal symptoms in patients who were addicted to opiate drugs and are enrolled in treatment programs in order to stop taking or continue not taking the drugs. Methadone is in a class of medications called opiate (narcotic) analgesics. Methadone works to treat pain by changing the way the brain and nervous system respond to pain. It also works as a substitute for opiate drugs of abuse by producing similar effects and preventing withdrawal symptoms in people who have stopped using these drugs.
Methadone comes as a tablet, a dispersible tablet (can be dissolved in liquid), a solution (liquid), and a concentrated solution (liquid that must be diluted before use) to take by mouth. When methadone is used to relieve pain, it may be taken every 4 to 12 hours. If you take methadone as part of a treatment program, your doctor will prescribe the dosing schedule that is best for you.
Your doctor may change your dose of methadone during your treatment. Your doctor may decrease your dose or tell you to take methadone less often as your treatment continues. Ask your doctor or pharmacist if you have any questions about how much methadone you should take or how often you should take the medication.
Methadone can be habit-forming. Call your doctor if you find that you want to take extra medication or notice any other unusual changes in your behavior or mood.
Do not stop taking methadone without talking to your doctor. Your doctor will probably want to decrease your dose gradually. If you suddenly stop taking methadone, you may experience withdrawal symptoms such as restlessness, teary eyes, runny nose, yawning, sweating, chills, muscle pain, and widened pupils (black circles in the middle of the eyes).
If you are using the dispersible tablets, place one tablet in a liquid such as water or citrus fruit juice. Wait 1 minute to allow the tablet to dissolve and then drink the entire mixture.
If you are using methadone oral concentrate solution, you should mix your prescribed dose of medication in at least 1 ounce (30 milliliters) of liquid such as water, citrus fruit juice, Kool Aid®, Tang®, apple juice, or Crystal Light®.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine.
If your doctor has told you to take methadone regularly, take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
loss of appetite
swelling of the hands, arms, feet, and legs
difficulty falling asleep or staying asleep
decreased sexual desire or ability
missed menstrual periods
Methadone may cause other side effects. Call your doctor if you have any unusual problems while you are taking this medication.
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
Store methadone in a safe place so that no one else can take it accidentally or on purpose. Keep track of how many tablets or how much solution or concentrated solution is left so you will know if any is missing.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
small, pinpoint pupils (black circles in the center of the eyes)
slow or shallow breathing
cool, clammy, or blue skin
loss of consciousness; coma
Keep all appointments with your doctor, laboratory, and clinic. Your doctor will want to check your response to methadone.
This prescription is not refillable. If you continue to experience pain after you finish methadone, call your doctor. If you take this medication on a regular basis, be sure to schedule appointments with your doctor so that you do not run out of medication.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Last Reviewed - 02/01/2009
AHFS® Consumer Medication Information. © Copyright, 2013. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.