Generic Name: methadone (oral/injection)
- What is methadone?
- What are the possible side effects of methadone?
- What is the most important information I should know about methadone?
- What should I discuss with my healthcare provider before using methadone?
- How should I use methadone?
- What happens if I miss a dose?
- What happens if I overdose?
- What should I avoid while using methadone?
- What other drugs will affect methadone?
- Where can I get more information?
What is methadone?
Methadone is also used as part of a drug addiction detoxification program. In people addicted to heroin or other narcotic drugs, methadone reduces withdrawal symptoms without causing the "high" associated with the drug addiction.
Methadone is available only from a certified pharmacy.
Methadone may also be used for purposes not listed in this medication guide.
What are the possible side effects of methadone?
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Opioid medicine can slow or stop your breathing, and death may occur. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.
Call your doctor at once if you have:
- weak or shallow breathing, breathing that stops during sleep;
- severe constipation;
- a light-headed feeling, like you might pass out;
- fast or pounding heartbeats, fluttering in your chest, shortness of breath; 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.
Serious side effects may be more likely in older adults and those who are malnourished or debilitated.
Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.
Common side effects may include:
- dizziness, drowsiness;
- nausea, vomiting;
- increased sweating; or
- pain, redness, or swelling where the medicine was injected.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What is the most important information I should know about methadone?
MISUSE OF OPIOID MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it.
Taking opioid medicine during pregnancy may cause life-threatening withdrawal symptoms in the newborn.
Fatal side effects can occur if you use opioid medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.
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.
What should I discuss with my healthcare provider 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 blockage in your stomach or intestines.
Methadone may cause a life-threatening heart rhythm disorder. Your heart function may need to be checked during treatment.
Tell your doctor if you have ever had:
- heart problems, long QT syndrome (in you or a family member);
- breathing problems, sleep apnea;
- a head injury, brain tumor, or seizures;
- drug or alcohol addiction, or mental illness;
- liver or kidney disease;
- urination problems; or
- problems with your gallbladder, pancreas, or thyroid.
If you use opioid 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 opioids may need medical treatment for several weeks.
Do not breast-feed. Methadone can pass into breast milk and cause drowsiness, breathing problems, or death in a nursing baby.
How should I use methadone?
Follow the directions on your prescription label and read all medication guides. Never use methadone in larger amounts, or for longer than prescribed. Tell your doctor if you feel an increased urge to take more of this medicine.
Never share opioid medicine with another person, especially someone with a history of drug abuse or addiction. MISUSE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it. Selling or giving away opioid medicine is against the law.
Methadone oral is taken by mouth. Methadone injection is injected into a muscle or under the skin, or given as an infusion into a vein. A healthcare provider may teach you how to properly use an injection by yourself.
Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).
Dissolve the dispersible tablet in water, orange juice, or other citrus-flavored non-alcoholic beverage.
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 prescription drugs.
When methadone is used as part of a treatment program for drug addiction or detoxification, your doctor may recommend that methadone be given to you by a family member or other caregiver.
You should not stop using methadone suddenly. Follow your doctor's instructions about tapering your dose.
Store at room temperature, away from moisture, heat, and light. Keep track of your medicine. Methadone is a drug of abuse and you should be aware if anyone is using it improperly.
Do not keep leftover opioid medication. Just one dose can cause death in someone using this medicine accidentally or improperly. Ask your pharmacist where to locate a drug take-back disposal program. If there is no take-back program, flush the unused medicine down the toilet.
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.
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 methadone at a lower dose.
Do not take two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose can be fatal, especially in a child or other person using this medicine without a prescription.
Overdose symptoms may include slow heart rate, severe drowsiness, muscle weakness, cold and clammy skin, pinpoint pupils, very slow breathing, or coma.
What should I avoid while using methadone?
Do not drink alcohol. Dangerous side effects or death could occur.
Avoid driving or operating machinery until you know how this medicine will affect you. Dizziness or severe drowsiness can cause falls, accidents, or severe injuries.
Grapefruit may interact with methadone and lead to unwanted side effects. Avoid the use of grapefruit products.
What other drugs will affect methadone?
You may have breathing problems or withdrawal symptoms if you start or stop taking certain other medicines. Tell your doctor if you also use an antibiotic, antifungal medication, heart or blood pressure medication, seizure medication, or medicine to treat HIV or hepatitis C.
Opioid medication can interact with many other drugs and cause dangerous side effects or death. Be sure your doctor knows if you also use:
- other narcotic medications--opioid pain medicine or prescription cough medicine;
- a sedative like Valium--diazepam, alprazolam, lorazepam, Ativan, Klonopin, Restoril, Tranxene, Versed, Xanax, and others;
- drugs that make you sleepy or slow your breathing--a sleeping pill, muscle relaxer, tranquilizer, antidepressant, or antipsychotic medicine; or
- drugs that affect serotonin levels in your body--a stimulant, or medicine for depression, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting.
This list is not complete. Other drugs may affect methadone, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.
Where can I get more information?
Your doctor or pharmacist can provide more information about methadone.
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