methadone

This medication is used to treat addiction to narcotic drugs (such as heroin) as part of an approved treatment program. Methadone belongs to a class of drugs known as narcotic (opiate) analgesics. It helps prevent withdrawal symptoms caused by stopping other narcotic drugs.

If you take this medication regularly and miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Read the Patient Information Leaflet if available from your pharmacist before you start using methadone and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Take this medication by mouth as directed by your doctor. You may take this drug with or without food. If you have nausea, it may help to take this drug with food. Ask your doctor or pharmacist about other ways to decrease nausea (such as lying down for 1 to 2 hours with as little head movement as possible). Do not chew or swallow the tablets. Before taking, dissolve the dose in 4 ounces (120 milliliters) of water or an acidic fruit drink (such as orange juice). Drink all of the mixture immediately. If there is any medication left in the cup, add a small amount of liquid and drink all of the mixture. Do not prepare a supply in advance. Do not inject this medication. The dosage is based on your medical condition and response to treatment. This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as restlessness, watering eyes, runny nose, nausea, sweating, muscle aches) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions immediately. When this medication is used for a long time, it may not work as well. Talk with your doctor if this medication stops working well. This medication may rarely cause abnormal drug-seeking behavior (addiction). This risk may be increased if you have abused alcohol or drugs in the past. Take this medication exactly as prescribed to lessen the risk of addiction. Stopping methadone maintenance treatment has a high risk of return to narcotic drug abuse. Tell your doctor if your condition persists or worsens.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug include: certain pain medications (mixed narcotic agonist-antagonists such as pentazocine, nalbuphine, butorphanol), narcotic antagonists (such as naltrexone), MAO inhibitors (isocarboxazid, linezolid, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine). Other medications can affect the removal of methadone from your body, which may affect how methadone works. Examples include St. John's wort, azole antifungals (such as itraconazole), HIV drugs (such as ritonavir), macrolide antibiotics (such as erythromycin), rifamycins (such as rifampin), drugs used to treat seizures (such as carbamazepine), among others. The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is taken with other products that may also affect breathing or cause drowsiness. Therefore, tell your doctor or pharmacist if you are taking other products such as alcohol, allergy or cough-and-cold products, medicine for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and psychiatric medicines (such as risperidone, amitriptyline, trazodone). Your medications or doses of your medications may need to be changed.

Do not share this medication with others. It is against the law and the medication may cause harm to others. This medication has been prescribed for your current condition only. Do not use it later for another condition unless told to do so by your doctor. A different medication may be necessary in those cases.

If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: slow/shallow breathing, slow heartbeat, loss of consciousness.

Before taking methadone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: brain disorders (such as head injury, tumor, seizures), breathing problems (such as asthma, sleep apnea, chronic obstructive pulmonary disease-COPD), kidney disease, liver disease, mental/mood disorders (such as confusion, depression, thoughts of suicide), personal or family history of regular use/abuse of drugs/alcohol, stomach/intestinal problems (such as blockage, constipation, diarrhea due to infection, paralytic ileus), difficulty urinating (such as due to enlarged prostate). This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages. Methadone may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm. Before using methadone, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death). Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using methadone safely. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Older adults may be more sensitive to the effects of this drug, especially dizziness, drowsiness, or urinary problems. During pregnancy, this medication should be used only when clearly needed. Pregnancy may affect the amount of this drug in your body, so tell your doctor right away if you become pregnant. Use for long periods or in high doses near the expected delivery date is not recommended because of possible harm to the unborn baby. Babies born to mothers who have used this medication for a long time may have withdrawal symptoms such as irritability, abnormal/persistent crying, vomiting, or diarrhea. Tell your doctor immediately if you notice any of these symptoms in your newborn. This drug passes into breast milk and may rarely have undesirable effects on a nursing infant. Tell the doctor immediately if your baby develops unusual sleepiness, difficulty feeding, or trouble breathing. Consult your doctor before breast-feeding or if you plan to stop breast-feeding.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

See also Warning section. Nausea, vomiting, constipation, lightheadedness, dizziness, dry mouth, drowsiness, or sweating may occur. Some of these side effects may decrease after you have been using this medication for a while. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. To prevent constipation, eat a diet adequate in fiber, drink plenty of water, and exercise. Consult your pharmacist for help in selecting a laxative (such as a stimulant type with stool softener). To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any unlikely but serious side effects, including: mental/mood changes (such as agitation, confusion, hallucinations), stomach/abdominal pain, difficulty urinating. Get medical help right away if you have any rare but serious side effects, including: seizure, unusual drowsiness/difficulty waking up. A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional. This drug may also be used to treat moderate to severe pain.

Methadone can cause severe, possibly fatal, breathing problems and heartbeat problems. These problems are more likely to happen when this medication is first started, or when you are switching from another narcotic drug to methadone, or when the dose is increased. Breathing problems from methadone may not happen right away after taking a dose. Most heartbeat problems have happened in people using large doses of methadone for pain relief, but this problem can also occur in people taking smaller doses to treat narcotic drug addiction. Do not increase your dose or take this medication more often than directed. Get medical help right away if you notice unusual slow/shallow breathing, fast/irregular heartbeat, severe dizziness, or fainting. Keep this medicine in a safe place to prevent theft, misuse, or abuse. If a child accidentally swallows this drug, get medical help right away.