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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: methadone (METH a done)
GENERIC: available FAMILY: Opiate-containing Painkillers
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

Opioids have been associated with a variety of effects on growth and development including abnormal behavior. Safe use in pregnancy has not been established. Infants born to mothers who have taken opioids regularly will exhibit withdrawal symptoms (including excessive crying, tremors, increased rate of breathing, diarrhea, vomiting, and fever) and are at increased risk for sudden death syndrome. Consult with your doctor if you are pregnant or thinking of becoming pregnant before you take this drug.

Breast-feeding Warning

Methadone is excreted in human milk. Because of the potential for serious adverse effects in nursing infants, you should not take methadone while nursing. If you are already on high-dose methadone maintenance and are already breast-feeding, you need to wean your infant gradually to prevent withdrawal symptoms.

Safety Warnings For This Drug [top]



Life-Threatening Respiratory Depression

Respiratory depression, including fatal cases, have been reported during initiation and conversion of patients to methadone, and even when the drug has been used as recommended and not misused or abused. Proper dosing and titration are essential and methadone Dispersible Tablets should only be prescribed by healthcare professionals who are knowledgeable in the use of methadone for detoxification and maintenance treatment of opioid addiction. Monitor for respiratory depression, especially during initiation of methadone Dispersible Tablets or following a dose increase. The peak respiratory depressant effect of methadone occurs later, and persists longer than the peak pharmacologic effect, especially during the initial dosing period.

Risks From Concomitant Use With Benzodiazepines or Other CNS Depressants

Concomitant use with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, is a risk factor for respiratory depression and death.

  • Reserve concomitant prescribing of benzodiazepines or other CNS depressants in patients in methadone treatment to those for whom alternatives to benzodiazepines or other CNS depressants are inadequate.
  • Follow patients for signs and symptoms of respiratory depression and sedation. If the patient is visibly sedated, evaluate the cause of sedation and consider delaying or omitting daily methadone dosing.

Life-Threatening QT Prolongation

QT interval prolongation and serious arrhythmia (torsades de pointes) have occurred during treatment with methadone. Most cases involve patients being treated for pain with large, multiple daily doses of methadone, although cases have been reported in patients receiving doses commonly used for maintenance treatment of opioid addiction. Closely monitor patients with risk factors for development of prolonged QT interval, a history of cardiac conduction abnormalities, and those taking medications affecting cardiac conduction for changes in cardiac rhythm during initiation and titration of methadone Dispersible Tablets.

Accidental Ingestion

Accidental ingestion of methadone Dispersible Tablets, especially by children, can result in fatal overdose of methadone.

Misuse, Abuse, and Diversion of Opioids

Methadone is an opioid agonist and Schedule II controlled substance with an abuse liability similar to other opioid agonists, legal or illicit.

Interactions with Drugs Affecting Cytochrome P450 Isoenzymes

The concomitant use of methadone with all cytochrome P450 3A4, 2B6, 2C19, 2C9 or 2D6 inhibitors may result in an increase in methadone plasma concentrations, which could cause potentially fatal respiratory depression. In addition, discontinuation of concomitantly used cytochrome P450 3A4, 2B6, 2C19, or 2C9 inducers may also result in an increase in methadone plasma concentration. Follow patients closely for respiratory depression and sedation, and consider dosage reduction with any changes of concomitant medications that can result in an increase in methadone levels.

Conditions For Distribution And Use Of Methadone Products For The Treatment of Opioid Addiction

For detoxification and maintenance of opioid dependence, methadone should be administered in accordance with the treatment standards cited in 42 CFR Section 8, including limitations on unsupervised administration.

Public Citizen Warning on New Methadone Dose

The FDA recommended dosages for patients starting methadone treatment for pain have been radically reduced.

The new approved starting dose is 2.5 milligrams to 10 milligrams every 8 to 12 hours – up to 30 milligrams per day.

The dangerous old starting dose for methadone was 2.5 milligrams to 10 milligrams every 3 to 4 hours as necessary – up to 80 milligrams per day.

No patient should ever receive more than 30 milligrams on day one for pain management, and, thereafter, dosage increases should be no more than 10 milligrams twice per week. Exceeding these limits can lead to death.

Facts About This Drug [top]

Methadone is a long-acting synthetic opiate that belongs to the same drug family as morphine. Methadone is approved by the Food and Drug Administration (FDA) for treatment of severe pain, detoxification treatment of opioid addiction and maintenance treatment of opioid addiction.[1]

In opiate-dependent individuals, methadone is given to replace shorter-acting drugs of abuse, such as heroin. It is given orally instead of intravenously, which reduces the harm caused by drug abuse. Taking the...

Methadone is a long-acting synthetic opiate that belongs to the same drug family as morphine. Methadone is approved by the Food and Drug Administration (FDA) for treatment of severe pain, detoxification treatment of opioid addiction and maintenance treatment of opioid addiction.[1]

In opiate-dependent individuals, methadone is given to replace shorter-acting drugs of abuse, such as heroin. It is given orally instead of intravenously, which reduces the harm caused by drug abuse. Taking the drug orally prevents withdrawal, suppresses heroin cravings and avoids unsafe injections[2] and death from overdose.[3] Methadone also reduces harm because pharmaceutical-grade methadone is formulated consistently, unlike street heroin, which can have variable doses and be contaminated. However, like any narcotic drug, methadone can be habit-forming.[4]

Methadone programs also reduce, but do not necessarily eliminate, illicit drug use, crime, risk of HIV infection and unemployment, and they help to stabilize social relations.[5]

The prescription of methadone for opiate indications such as methadone maintenance is limited to registered drug treatment facilities and certain pharmacies. When patients who have been receiving morphine (MS CONTIN, ROXANOL), hydromorphone (DILAUDID) or fentanyl patches (DURAGESIC) experience intolerable adverse effects, or if their pain is not well controlled, a switch to methadone may be considered. Several protocols determine the amount of methadone to use when switching to avoid withdrawal. The amount depends on the dose of the other narcotic and the degree of tolerance developed, if any. Switches typically require several days.[6],[7],[8]

The professional product label (also known as the package insert) for methadone has long carried a black-box warning, the FDA's strongest warning, about respiratory depression (slowed breathing) and fatal heart rhythm disturbances. Black-box warnings usually are reserved for those drugs that have caused death or serious injury to patients.[9]

Patients who frequently use medication to relieve headache pain may develop a condition known as medication overuse headache (MOH). According to a 2004 review published in the medical journal Lancet Neurology,[10] there is substantial evidence that all headache drugs can cause MOH in patients who use these drugs excessively. Narcotic or opioid painkillers that are derivatives of morphine and codeine can cause MOH.[10]

Patients experiencing MOHs should discuss with their doctors the important details of their headaches and, depending on their individual case, the type of withdrawal from the MOH-causing drugs that is best for them.[11]

Adverse effects

The most frequent and persistent adverse effect of opioids such as methadone is constipation. The other adverse effects of methadone are similar to those of morphine. The risk of slowed breathing increases when used with alcohol, benzodiazepines such as diazepam (VALIUM) and illicit narcotics such as heroin. To avoid respiratory depression, the dose is increased slowly.[12] Gradually, the interval between doses can be lengthened.[13] The toxic dose of methadone is much lower in people who have not used it or other narcotics before.[12]

QT prolongation

The QT interval is the length of time it takes the large chambers of the heart to electrically discharge and recharge. A prolongation of the QT interval can lead to torsades de pointes, a type of heart rhythm disturbance, and sudden death.

It is risky to take methadone in combination with other drugs known to prolong the QT interval. The only extensive list of drugs that prolong QT intervals is maintained by the University of Arizona Health Sciences Center at http://www.torsades.org.

Regulatory actions surrounding methadone

2006: In November, the FDA issued a public health advisory after the agency received reports of deaths and serious respiratory and cardiovascular adverse events associated with the use of methadone. These adverse events appear to be the result of unintentional methadone overdoses, drug interactions and the heart toxicity of the drug.[14]

In its warning, the FDA made new recommendations for a drastic reduction in the starting dose for pain. The adjusted recommendation, which is a more than 2.5-fold reduction in the maximum dosage for the initial treatment of pain, is intended to prevent some of the life-threatening adverse reactions associated with the use of methadone. This dosage is more in line with the lower recommended starting dose of methadone when it is used for narcotic detoxification. The new starting dose is 2.5 milligrams to 10 milligrams every 8 to 12 hours – up to 30 milligrams per day.

2016: The FDA issued a safety warning for the entire opioid class of drugs concerning potential harmful interactions with other medications, problems with the adrenal glands and decreased sex hormone levels.[15]

The FDA required the addition of a black-box warning to opioid and benzodiazepine drugs stating that profound sedation, depressed breathing, coma and death can occur when these medications are used together.

2017: The FDA issued an advisory that when methadone is used to treat opioid addiction with benzodiazepines, a treatment plan should be developed to reduce the risk of serious adverse effects. The FDA required that the drug product label be updated to reflect this information.[16]

Before You Use This Drug [top]

Do not use if you have or have had:

  • diarrhea from pseudomembranous colitis caused by certain antibiotics (cephalosporins, clindamycin topical, lincomycin, or penicillin)
  • diarrhea caused by poisoning
  • respiratory disease or impairment

Tell your doctor if you have or have had:

  • allergy to methadone
  • pregnancy or are breast-feeding
  • abdominal problems
  • asthma
  • respiratory problems
  • heart problems
  • convulsions
  • drug abuse
  • alcohol abuse
  • emotional problems
  • suicide attempts or suicidal thoughts
  • gallbladder problems
  • recent gastrointestinal surgery
  • head injury
  • liver problems
  • low thyroid activity
  • bowel disease
  • enlarge prostate
  • kidney or urinary problems or recent urinary tract surgery

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Visit your doctor regularly to check your progress during long-term therapy.
  • Avoid alcohol and other central nervous system drugs, such as alprazolam (XANAX) and diazepam (VALIUM), unless approved by your doctor.
  • Do not drive or operate hazardous equipment until you know whether you become dizzy or drowsy or have a false sense of well-being when taking methadone.
  • When you change position from lying down to sitting to standing, do so gradually.
  • Lie down if you become dizzy, drowsy, lightheaded, or nauseous.
  • If you plan to have any surgery, including dental, tell your doctor that you take this drug.
  • If you have dry mouth, use sugarless gum, hard candy, or a saliva substitute to prevent cavities. Check with your dentist if dry mouth continues for more than two weeks.

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip the dose if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Dissolve dispersible tablets in water or fruit juice.
  • Dilute oral concentrate with at least one ounce of water, unless prediluted by your provider.
  • Do not suddenly stop taking this drug without checking with your doctor to find out if you need to taper off.
  • If you stop taking this medication, remember that adverse effects can still occur even after drug is discontinued.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

Methadone taken with these drugs may increase the methadone level in the blood and could lead to overdose of methadone: KALETRA, lopinavir, naltrexone, nelfinavir, nevirapine, REVIA, RIFAMATE, rifampin, RIFATER, RIMACTANE, TRAMADOL, ULTRAM, VIRACEPT, VIRAMUNE.

Methadone with other drugs that also depress the central nervous system or have anticholinergic effects could add to adverse effects, such as drowsiness and constipation. Doses may need adjusting. These include: alcohol, antidepressants (for example, imipramine [TOFRANIL]), antihistamines (for example, diphenhydramine [BENADRYL]), antinausea agents (for example, prochlorperazine [COMPAZINE]), antipsychotic agents (for example, chlorpromazine [THORAZINE]), motion sickness pills (for example, meclizine [ANTIVERT]), other narcotics (for example, morphine), sedatives (for example, oxazepam [SERAX]), tranquilizers (for example, diazepam [VALIUM]).

Adverse Effects [top]

Call your doctor immediately if you experience:

  • difficult, irregular, or slow breathing; wheezing
  • facial swelling
  • unusual excitement or restlessness
  • confusion
  • pounding, rapid, or slow heartbeat
  • hallucinations
  • blood pressure decrease
  • profuse sweating
  • flushed or red face
  • mental depression
  • bloating
  • constipation that is severe
  • nausea or vomiting
  • stomach cramps or pain

Contact your doctor if these symptoms continue:

  • more frequent, difficult, or painful urination, or decrease in the amount of urine
  • stomach cramps or pain
  • skin rash, hives, and/or itching
  • vision changes
  • constipation
  • nausea or vomiting
  • dizziness, fainting, lightheadedness
  • drowsiness
  • general feeling of discomfort or illness
  • dry mouth
  • appetite decrease
  • false sense of well-being
  • headache
  • nervousness
  • trouble sleeping
  • tiredness or weakness that is unusual

Call your doctor if these symptoms continue after you stop taking this drug:

  • sweating
  • yawning
  • appetite loss
  • gooseflesh
  • fast heartbeat
  • irritability, nervousness, restlessness
  • dilated pupils
  • tremor, twitching, shivering
  • body aches
  • abdominal cramps
  • diarrhea
  • fever, runny nose, or sneezing
  • insomnia
  • weakness

Signs of overdose:

  • blood pressure drop
  • difficult breathing
  • cold, clammy skin
  • confusion
  • convulsions
  • severe dizziness
  • severe drowsiness
  • slow heartbeat
  • nervousness or restlessness
  • pinpoint pupils
  • severe weakness
  • unconsciousness

If you suspect an overdose, call this number to contact your poison control center: (800) 222-1222.

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • drug, blood, or urine tests
  • respiratory function tests

last reviewed February 29, 2024