How does this medication work? What will it do for me?

This medication contains two ingredients: naltrexone and bupropion. Naltrexone is a pure opioid antagonist. Bupropion belongs to the family of antidepressants. Together, they work in different areas of the brain to control appetite and cravings.

Together, they are used in addition to exercise and a reduced-calorie diet to help reduce weight for adults who are clinically obese or overweight and have high blood pressure, type 2 diabetes, or high cholesterol.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each round, biconvex, blue, film-coated, extended-release tablet, debossed with NB-890 on one side, contains 8 mg of naltrexone hydrochloride and 90 mg of bupropion hydrochloride. Nonmedicinal ingredients: colloidal silicon dioxide, crospovidone, edetate disodium, FD&C Blue No. 2 indigo carmine aluminum lake, hydroxypropyl cellulose, ypromellose, lactose anhydrous, lactose monohydrate, L-cysteine hydrochloride, macrogol/peg, magnesium stearate, microcrystalline cellulose, polyvinyl alcohol-part hydrolyzed, talc, and titanium dioxide.

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How should I use this medication?

The usual starting dose of this medication is one tablet taken by mouth once daily, in the morning for the first week. For the second week, the dose is one tablet twice a day, once in the morning and one with the evening meal. The dose is increased by 1 tablet daily each week until the recommended maximum daily dose of two tablets taken twice daily.

Naltrexone-bupropion may be taken with meals. High-fat meals should be avoided, as this increases the amount of medication in the body and can increase the side effects. Swallow the tablets whole and do not cut, crush, or chew them.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor.

If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to naltrexone, bupropion, or any ingredients of this medication
  • are pregnant
  • are taking another medication that contains bupropion (e.g., Wellbutrin XL®, Wellbutrin® SR, or Zyban®)
  • are currently taking thioridazine (an antipsychotic medication)
  • are receiving opiate analgesics (e.g., narcotics medications such as oxycodone and codeine) or opiate agonists (e.g., methadone) or partial agonists (e.g., buprenorphine)
  • are abruptly discontinuing alcohol, benzodiazepines (e.g., diazepam, clonazepam, lorazepam), other sedatives (e.g., phenobarbital), or seizure medications
  • are experiencing opiate withdrawal
  • have uncontrolled high blood pressure
  • have or have had an eating disorder (bulimia or anorexia nervosa)
  • have severely decreased liver function
  • have end-stage kidney failure
  • have a seizure disorder or history of seizures
  • have taken a monoamine oxidase inhibitor (MAO inhibitor; e.g., phenelzine, tranylcypromine) within the past 2 weeks

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • abdominal pain
  • blurred vision
  • constipation
  • diarrhea
  • dizziness
  • dry mouth
  • fatigue
  • flu-like symptoms (e.g., muscle aches, cough, fatigue, sudden lack of energy, sore throat, fever)
  • hair loss
  • headache
  • heartburn
  • itching
  • metallic taste in the mouth
  • nausea
  • rash
  • sensation of spinning
  • sweating
  • tremor
  • trouble paying attention
  • trouble sleeping
  • unusual dreams
  • vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • acting on dangerous impulses
  • angry or violent behaviour
  • new or worsened anxiety
  • aggressiveness
  • agitation
  • episodes of mania (e.g., feeling very high, talking fast, risk taking, needing less sleep)
  • hallucinations (seeing or hearing things that are not there)
  • increased blood pressure (e.g., headache, nosebleed, dizziness, facial flushing)
  • increased heart rate
  • migraine
  • panic attacks
  • paranoia
  • restlessness
  • ringing in the ears
  • new or worse symptoms of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
  • signs of liver problems (yellowing of the eyes or skin, abdominal pain, nausea, vomiting, dark urine)
  • symptoms of glaucoma (e.g., blurred vision, seeing halos of bright colours around lights, red eyes, increased pressure in your eyes, eye pain or discomfort)
  • symptoms of low blood sugar (e.g., cold sweat, cool pale skin, headache, fast heartbeat, weakness)
  • symptoms of lupus (e.g., fever, fatigue, joint pain or swelling, muscle aches, skin rash)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • opioid withdrawal (if opioids were taken less than 7 to 10 days before starting naltrexone-bupropion) (e.g., nausea and vomiting, anxiety, trouble sleeping, hot and cold flashes, perspiration, muscle cramps, diarrhea)
  • opioid overdose (if taking opioids) (e.g., trouble breathing; slow, shallow breathing; very drowsy; very dizzy; confused; feeling faint)
  • signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
  • seizures
  • symptoms of serotonin toxicity (e.g., confusion, fast heartbeat, hallucinations, restlessness, shaking, shivering, sudden jerking of muscles, sweating)
  • thoughts of or attempts of suicide or self-harm

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Accidental ingestion: If you are dependent on narcotics and you ingest this medication, you could experience severe symptoms of withdrawal including confusion, nausea, shakiness, sweating, anxiety, visual hallucinations, vomiting, or diarrhea. Avoid taking narcotic medications while you are taking naltrexone-bupropion.

Diabetes: Weight loss often causes decreased blood glucose. As a result, using naltrexone-bupropion may cause episodes of low blood sugar when taken by people with diabetes who are taking certain oral medications to control blood sugar. You may find it necessary to monitor your blood sugar more frequently while using this medication.

If you have diabetes or are at risk for developing diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Drowsiness/reduced alertness: Bupropion may affect the mental or physical abilities needed to drive or operate machinery. Avoid driving, operating machinery, or performing other hazardous tasks until you have determined how this medication affects you.

Heart disease: Bupropion can increase blood pressure and heart rate. It is not known whether it is safe for use by people with a recent history of heart attack or unstable heart disease. If you have had a heart attack within the past 6 months, have an irregular heartbeat, high blood pressure, congestive heart failure or a recent stroke, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Galactose intolerance/glucose malabsorption: This medication contains lactose. If you have lactose or galactose intolerance you should not take this medication.

Glaucoma: This medication may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking this medication.

Identical medications: Wellbutrin®, Zyban® and several other medications contain bupropion. Revia® and Relistor® contain naltrexone. If you are taking naltrexone-bupropion, do not take any other product containing bupropion or naltrexone, as the risk of side effects increases with an increased dosage.

Interference with opiate-containing mediations: Because this medication works by blocking the effects of opiates, it will reduce the effectiveness of narcotic pain relievers. It may also interfere with other medications that contain opiates such as certain cough and cold medications, antidiarrheal medications, and some analgesics (pain medications). Trying to overcome the blocking effects of naltrexone by taking larger doses of narcotics may result in severe side effects of the narcotic. Talk to your doctor or pharmacist about non-opiate containing alternatives.

Kidney function:  Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have kidney problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. This medication is not recommended for people with end-stage kidney disease.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Naltrexone-bupropion is not recommended for people with severely decreased liver function.

Naltrexone-bupropion has been reported to cause decreased liver function. If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Lupus: There may be an association between taking naltrexone – bupropion and the autoimmune conditions systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE). If you develop any skin rash (particularly on the face), fatigue, joint pain, or swelling, contact your doctor as soon as possible.

Mental health: Bupropion may trigger mania and make behaviour and thought disturbances worse for people who have mental health conditions. It may also cause symptoms of psychosis and mania to develop for people who have not had these symptoms before. If you experience symptoms such as hallucinations, mania (feeling unusually over-excited or uninhibited), or delusional thinking, or notice them in a family member who is taking this medication, contact your doctor as soon as possible. If you have mental health concerns, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Seizure risk: Bupropion may increase the risk of seizures. If you are at risk of seizures, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Things that increase the risk of seizures include:

  • addiction to cocaine, stimulants, or opiates (such as morphine)
  • diabetes treated with oral medications or insulin
  • excessive alcohol use
  • history of head trauma or seizures (including epilepsy)
  • severe liver problems
  • tumours of the brain or spinal cord
  • use of other medications that make seizures more likely (e.g., antipsychotics, antidepressants, lithium, theophylline, steroids)
  • use of over-the-counter stimulants or appetite suppressants

Serotonin toxicity: Severe reactions are possible when naltrexone - bupropion is combined with other medications that act on serotonin, such as tricyclic antidepressants and serotonin reuptake inhibitors, medications used to treat depression. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, and changes in mental state including delirium and agitation. Coma and death are possible.

Suicidal or agitated behaviour, or other behaviour changes: People taking this medication may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves), or they may want to hurt themselves or others. These symptoms may occur within several weeks after people start taking this medication. If you experience these side effects or notice them in a family member who is taking this medication, contact your doctor immediately. Your doctor will monitor you for emotional and behavioural changes while you are taking bupropion.

Pregnancy: Weight loss does not benefit a woman during pregnancy and may cause harm to the developing baby. Use of either of these medications may also cause harm to the developing baby. For these reasons, this medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: Both naltrexone and bupropion pass into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: Seniors may be at an increased risk of side effects due to age-related decreased kidney or liver function.

What other drugs could interact with this medication?

There may be an interaction between naltrexone – bupropion and any of the following:

  • alcohol
  • amantadine
  • amphetamines (dextroamphetamine, lisdexamfetamine)
  • antipsychotics (e.g., amoxapine, chlorpromazine, haloperidol, pimozide, risperidone, thioridazine)
  • apomorphine
  • atomoxetine
  • bromocriptine
  • caffeine
  • carbamazepine
  • carvedilol
  • clopidogrel
  • dexmethylphenidate
  • dextromethorphan
  • digoxin
  • doxorubicin
  • eliglustat
  • fesoterodine
  • flecainide
  • glyburide
  • HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., efavirenz, nevirapine)
  • levodopa
  • linezolid
  • lithium
  • lopinavir
  • lumacaftor and ivacaftor
  • metoclopramide
  • methadone
  • metoprolol
  • methylene blue
  • methylphenidate
  • methylnaltrexone
  • mexiletine
  • mifepristone
  • mirtazapine
  • monoamine oxidase inhibitors (MAO inhibitors; e.g., phenelzine, tranylcypromine, moclobemide, selegilene) - bupropion should not be started until at least 14 days after MAO inhibitors are stopped
  • naloxegol
  • narcotic pain relievers (e.g., codeine, fentanyl, hydrocodone, morphine, oxycodone, tramadol)
  • ozanimod
  • pitolisant
  • phenytoin
  • phenobarbital
  • pramipexole
  • prochlorperazine
  • propafenone
  • propranolol
  • rifampin
  • ritonavir
  • ropinirole
  • rotigotine
  • selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
  • serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
  • tamoxifen
  • tamsulosin
  • tetrabenazine
  • theophylline
  • tolterodine
  • tricyclic antidepressants (e.g., nortriptyline, imipramine, desipramine)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/drug/getdrug/Contrave