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. It is available only from a certified pharmacy.
Methadone is used for around-the-clock treatment of severe pain. This medicine is not for use on an as-needed basis for pain.
You should not use methadone if you have severe asthma or breathing problems, or a blockage in your stomach or intestines.
MISUSE OF METHADONE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH, especially in a child or other person using the medicine without a prescription. 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. Your heart function may need to be checked during treatment.
Before taking this medicine
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.
To make sure methadone is safe for you, 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 during pregnancy, your baby could be born with life-threatening withdrawal symptoms, and may need medical treatment for several weeks.
Do not breastfeed. Methadone can pass into breast milk and cause drowsiness, breathing problems, or death in a nursing baby.
How should I use methadone?
Use methadone exactly as prescribed by your doctor. Follow the directions on your prescription label and read all medication guides or instruction sheets. Never use methadone in larger amounts, or for longer than prescribed. Tell your doctor if you feel an increased urge to use more of this medicine.
Never share opioid medicine with another person, especially someone with a history of drug addiction. MISUSE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medicine where others cannot get to it. Selling or giving away this medicine is against the law.
Methadone oral is taken by mouth. The injection is given directly into a vein.
Measure liquid medicine with the supplied measuring device (not a kitchen spoon).
Dissolve the dispersible tablet in water, orange juice, or other citrus-flavored non-alcoholic beverage. Stir and drink this mixture right away.
Never crush a pill to inhale the powder or inject it into your vein. This could result in death.
You should not stop using methadone suddenly. Ask your doctor before stopping the medicine.
Store at room temperature, away from moisture, heat, and light. Keep your medicine in a place where no one can use it improperly.
Do not keep leftover medicine. Just one dose can cause death in someone using it accidentally or improperly. Ask your pharmacist about a drug take-back program, or 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 your dosing schedule 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 person using opioid medicine without a prescription. Overdose symptoms may include severe drowsiness, pinpoint pupils, slow breathing, or no breathing.
Your doctor may recommend you get naloxone (a medicine to reverse an opioid overdose) and keep it with you at all times. A person caring for you can give the naloxone if you stop breathing or don’t wake up. Your caregiver must still get emergency medical help and may need to perform CPR (cardiopulmonary resuscitation) on you while waiting for help to arrive.
Anyone can buy naloxone from a pharmacy or local health department. Make sure any person caring for you knows where you keep naloxone and how to use it.
What should I avoid while using methadone?
Do not drink alcohol. Dangerous side effects or death could occur.
Avoid driving or hazardous activity until you know how methadone will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.
Grapefruit may interact with methadone and cause side effects. Avoid consuming grapefruit products.
Methadone side effects
Get emergency medical help if you have signs of an allergic reaction to methadone: 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 give naloxone and/or 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;
- low cortisol levels–nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness; or
- serotonin syndrome – agitation, hallucinations, fever, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, diarrhea.
Serious breathing problems may be more likely in older adults and people who are debilitated or have wasting syndrome or chronic breathing disorders.
Common methadone 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 other drugs will affect methadone?
You may have a fatal methadone overdose if you start or stop using certain other medicines. Tell your doctor about all your medications.
Many other drugs can be dangerous when used with opioid medicine. Tell your doctor if you also use:
- medicine for allergies, asthma, blood pressure, motion sickness, irritable bowel, or overactive bladder;
- other opioid medicines;
- a benzodiazepine sedative like Valium, Klonopin, or Xanax;
- sleep medicine, muscle relaxers, or other drugs that make you drowsy; or
- drugs that affect serotonin, such as antidepressants, stimulants, or medicine for migraines or Parkinson’s disease.