This medication is used with a doctor-approved exercise, behavior change, and reduced-calorie diet program to help you lose weight. It is used by certain overweight people, such as those who are obese or have weight-related medical problems. Losing weight and keeping it off can lessen the many health risks that come with obesity, including heart disease, diabetes, high blood pressure, and a shorter life.

Naltrexone belongs to a class of drugs known as opiate antagonists. Bupropion is an antidepressant that helps to restore the balance of certain natural substances (dopamine, norepinephrine) in the brain. These two medications work together on separate parts of the brain to reduce appetite and how much you eat.

Most opiates should not be used for 7 to 10 days before starting naltrexone, but some opiate drugs (such as methadone) should not be used for 10 to 14 days before starting naltrexone. Ask your doctor or pharmacist for more details.

Other forms of naltrexone or bupropion are used to treat a variety of conditions including depression, other mental/mood disorders, smoking cessation, addiction to opioid medication, and alcohol abuse. This combination product is not approved for these other uses.

Discuss the risks and benefits of this medication, as well as other ways to lose weight, with your doctor.

Read the Medication Guide if available from your pharmacist before you start taking naltrexone/bupropion and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth with a low-fat meal as directed by your doctor, usually twice daily.

You may have trouble sleeping when you start taking this drug. Do not take your evening dose too close to bedtime.

Swallow the tablets whole. Do not crush or chew this medication. Doing so can release all of the drug at once, increasing the risk of side effects such as seizures.

The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Your dose will be slowly increased to lower the risk of seizures and to limit side effects such as sleeplessness, symptoms of withdrawal from opiates, and high blood pressure. Do not increase your dose, take it more often, or stop taking it without your doctor's approval.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Tell your doctor if you have not lost weight after 16 weeks on this medication.

See also Warning, How to Use, and Precautions sections.

Nausea, vomiting, constipation, stomach pain, headache, dizziness, trouble sleeping, increased sweating, flushing, and dry mouth or strange taste in the mouth may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor 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 serious side effects, including:

• mental/mood changes (anxiety, agitation, confusion, memory loss)
• uncontrolled movements (tremor)
• ringing in the ears
• fainting
• severe headache
• fast/pounding/irregular heartbeat
• chest pain

Get medical help right away if you have any very serious side effects, including:

• eye pain/swelling/redness
• widened pupils
• vision changes (such as seeing rainbow around lights at night)

If you have been taking opioid medications regularly, you could have withdrawal symptoms within minutes after taking naltrexone. Tell your doctor right away if you have any of the following symptoms of opioid withdrawal:

• mental/mood changes (such as anxiety/irritability)
• fast breathing
• yawning
• sweating
• watering eyes
• goose bumps
• muscle twitching

This drug may rarely cause seizures. Get medical help right away if you have a seizure. If you have a seizure while taking bupropion, you should not take this drug again.

Naltrexone may rarely cause serious (possibly fatal) liver disease. The risk is increased when larger doses are used. Discuss the risks and benefits with your doctor. Stop using this medication and tell your doctor right away if you have symptoms of liver damage, including:

• nausea/vomiting that doesn't stop
• loss of appetite
• severe stomach/abdominal pain
• yellowing eyes/skin
• dark urine

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 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

See also Warning section.

Before taking naltrexone/bupropion, 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:

• high blood pressure
• heart disease (such as heart failure, recent heart attack)
• mental/mood disorders (such as bipolar disorder/thoughts of suicide)
• diabetes
• current or recent use (in the last 7-14 days) of any type of opioid drug (such as morphine/methadone/buprenorphine)
• kidney disease
• liver disease (such as cirrhosis)
• high pressure in the eye (glaucoma)
• use/abuse of drugs/alcohol
• seizures or conditions that increase your risk of seizures (including brain/head injury, brain tumors, arteriovenous malformation, eating disorders such as bulimia/anorexia nervosa)

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis). Alcohol may also increase your risk of seizures.

After stopping treatment with this medication, you may be more sensitive to opioids, increasing your risk of possibly life-threatening side effects from opioids (such as decreased breathing, loss of consciousness).

This medication blocks the effects of opiate drugs (including heroin) and similar drugs (opioids). However, large doses of heroin or opioids can overcome this block. Trying to overcome this block is very dangerous and may cause serious injury, loss of consciousness, and death. Follow your doctor's instructions closely.

Do not take this product with any other product that contains bupropion (such as antidepressants or smoking cessation drugs) since large doses of bupropion are more likely to cause seizures.

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 side effects of this drug, especially dizziness. Dizziness can increase the risk of falling.

This medication must not be used during pregnancy. Weight loss during pregnancy is not recommended and may harm an unborn baby. If you become pregnant or think you may be pregnant, tell your doctor right away.

This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.

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:

• dextromethorphan
• diarrhea medications (such as diphenoxylate)
• disulfiram
• pimozide
• opioid pain or cough relievers (such as codeine, hydrocodone)
• tamoxifen
• thioridazine

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and after treatment with this medication. Ask your doctor when to start or stop taking this medication.

This medication may interfere with certain medical/lab tests (such as urine tests for amphetamine, opioid drug tests, and brain scan for Parkinson's disease), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: seizures, hallucinations, fast/slow/irregular heart rate, loss of consciousness.

Do not share this medication with others.

Lab and/or medical tests (such as blood pressure, pulse, liver function, eye exams) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

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.