Methadone Oral Tablet

Methadone can interact with other medications, vitamins, or herbs you may be taking. An interaction is when a substance changes the way a drug works. This can be harmful or prevent the drug from working well.

To help avoid interactions, your doctor should manage all of your medications carefully. Be sure to tell your doctor about all medications, vitamins, or herbs you’re taking. To find out how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Alcohol interaction

The use of drinks that contain alcohol can increase your risk of sedation, slowed breathing, coma (being unconscious for a long time), and death from methadone. If you drink alcohol, talk to your doctor. You may need to be monitored for low blood pressure, breathing problems, and sedation.

Medications that might interact with this drug

Drugs that you should not use with methadone

Do not take these drugs with methadone. Doing so can cause dangerous effects in the body. Examples of these drugs include:

• Pentazocine, nalbuphine, butorphanol, and buprenorphine. These drugs may reduce methadone’s pain-relieving effects. This might cause withdrawal symptoms.

Interactions that increase your risk of side effects

• Increased side effects from other drugs: Taking methadone with certain medications raises your risk of side effects from those drugs.  Examples of these drugs include:
  • Zidovudine.  Side effects include headache, tiredness, loss of appetite, nausea, and vomiting.

• Side effects from methadone: Taking methadone with certain medications raises your risk of side effects from methadone. This is because the amount of methadone in your body is increased. Examples of these drugs include:
  • Cimetidine. Taking this drug with methadone may cause more drowsiness and slowed breathing. Your doctor might adjust your dose of methadone, depending on how severe your side effects are.
  • Antibiotics, such as clarithromycin and erythromycin. Taking these drugs with methadone may cause more drowsiness and slowed breathing. Your doctor might adjust your dose of methadone, depending on how severe your side effects are.
  • Antifungal drugs, such as ketoconazole, posaconazole, and voriconazole. Taking these drugs with methadone may cause more drowsiness and slowed breathing. Your doctor might adjust your dose of methadone, depending on how severe your side effects are.
  • Human immunodeficiency virus (HIV) drugs, such as ritonavir or indinavir. Taking these drugs with methadone may cause more drowsiness and slowed breathing. Your doctor might adjust your dose of methadone, depending on how severe your side effects are.

• Increased side effects from both drugs:Taking methadone with certain medications raises your risk of side effects. This is because methadone and these other medications can cause the same side effects. As a result, these side effects can be increased. Examples of these drugs include:
  • Allergy drugs, such as diphenhydramine and hydroxyzine. Taking these drugs with methadone may cause urinary retention (not being able to fully empty your bladder), constipation, and slowed movement in your stomach and bowels. This can lead to a severe bowel obstruction.
  • Urinary incontinence drugs, such as tolterodine and oxybutynin. Taking these drugs with methadone may cause urinary retention (not being able to fully empty your bladder), constipation, and slowed movement in your stomach and bowels. This can lead to a severe bowel obstruction.
  • Benztropine and amitriptyline. Taking these drugs with methadone may cause urinary retention (not being able to fully empty your bladder), constipation, and slowed movement in your stomach and bowels. This can lead to a severe bowel obstruction.
  • Antipsychotics, such as clozapine and olanzapine. Taking these drugs with methadone may cause urinary retention (not being able to fully empty your bladder), constipation, and slowed movement in your stomach and bowels. This can lead to a severe bowel obstruction.
  • Heart rhythm drugs, such as, quinidine, amiodarone, and dofetilide. Taking these drugs with methadone may increase your risk of longer QT intervals and cause heart rhythm problems.
  • Amitriptyline. Taking this drug with methadone may increase your risk of longer QT intervals and cause heart rhythm problems.
  • Diuretics, such as furosemide and hydrochlorothiazide. Taking these drugs together can change your electrolyte levels. This can cause heart rhythm problems.
  • Laxatives. Taking these drugs together can change your electrolyte levels. This can cause heart rhythm problems.

Interactions that can make your drugs less effective

• When methadone is less effective: When methadone is used with certain drugs, it may not work as well to treat your condition. This is because the amount of methadone in your body may be decreased. Examples of these drugs include:
  • Anticonvulsants, such as phenobarbital, phenytoin, and carbamazepine. These drugs can cause methadone to stop working. This could cause withdrawal symptoms. Your doctor may change your dose of methadone.
  • Human immunodeficiency virus (HIV) drugs such as abacavir, darunavir, efavirenz, nelfinavir, nevirapine, ritonavir, and telaprevir. Your doctor will monitor you closely for symptoms of withdrawal. They’ll adjust your dose as needed.
  • Antibiotics, such as rifampin and rifabutin. These drugs can cause methadone to stop working. This could cause withdrawal symptoms. Your doctor may change your dose of methadone.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking. Methadone warnings

People with kidney problems

If you have kidney problems or a history of kidney disease, you may not be able to clear this drug from your body well. This may increase the levels of methadone in your body and cause more side effects. Your doctor should watch you closely if you take this drug.

People with liver problems

If you have liver problems or a history of liver disease, you may not be able to process this drug well. This may increase the levels of methadone in your body and cause more side effects. Your doctor should watch you closely if you take this drug.

People with breathing problems

This drug can cause breathing problems. It can also make breathing problems you already have worse. This can be fatal (cause death). If you have breathing problems, severe asthma, or have an asthma attack, you should talk to your doctor about whether this drug is safe for you.

People with a gastrointestinal (GI) obstruction

This drug can cause constipation and increase your risk of a GI obstruction. If you have a history of GI obstructions or you currently have one, you should talk to your doctor about whether this drug is safe for you. If you have a paralytic ileus (lack of muscle tone in the intestines that can cause GI obstructions), you shouldn’t take this drug.

People with seizures

This drug may cause more seizures in people with epilepsy. If your seizure control gets worse, call your doctor.

People with a head injury

This drug may cause increased pressure in your brain. This can raise your chance of complications or cause death. If you have a recent head injury, it increases your risk of having breathing problems from methadone. Talk to your doctor about whether this drug is safe for you.

Pregnant women

Methadone is a category C pregnancy drug. That means two things:

1. Research in animals has shown adverse effects to the fetus when the mother takes the drug.
2. There haven’t been enough studies done in humans to be certain how the drug might affect the fetus.

Talk to your doctor if you’re pregnant or planning to become pregnant. This drug should only be used if the potential benefit justifies the potential risk to the fetus.

Children who are born to mothers who used this drug for a long time during pregnancy are at risk of neonatal withdrawal syndrome. This can be life-threatening to the child.

Women who are breast-feeding

Methadone may pass into breast milk and may cause side effects in a child who is breast-fed. These side effects include slowed breathing and sedation. 

Talk to your doctor if you breast-feed your child. You may need to decide whether to stop breast-feeding or stop taking this medication.

For seniors

The kidneys of older adults may not work as well as they used to. This can cause your body to process drugs more slowly. As a result, more of a drug stays in your body for a longer time. This raises your risk of side effects.

For children

The safety and effectiveness of this drug haven’t been established in children. It shouldn’t be used in people younger than 18 years.

Children who accidentally take this drug have a high risk of death from overdosing.

When to call the doctor

Call your doctor if the dose you’re taking doesn’t control your pain.

Call your doctor right away if you become pregnant while taking this drug. 

Allergies

Methadone can cause a severe allergic reaction. Symptoms can include:

• trouble breathing
• swelling of your throat or tongue

If you have an allergic reaction, call your doctor or local poison control center right away. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).