Reviewed on 2/9/2022

What Is Bupropion/Naltrexone and How Does It Work?

Bupropion/Naltrexone is a prescription medication used for treating obesity.

  • Bupropion/Naltrexone is available under the following different brand names: Contrave

What Are Dosages of Bupropion/Naltrexone?

Adult dosage

Extended-release tablet

  • 90mg/8mg


Adult dosage

  • 1 tablet (90mg/8mg) initially week 1; increase by 1 tablet/day each subsequent week until a daily maintenance dose of 2 tablets twice daily (360 mg bupropion/32 mg naltrexone) is achieved at the start of week 4 

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."

What Are Side Effects Associated with Using Bupropion/Naltrexone?

Common side effects of Bupropion/Naltrexone include:

  • nausea
  • constipation
  • headache
  • vomiting
  • dizziness
  • trouble sleeping
  • dry mouth
  • diarrhea 

Serious side effects of Bupropion/naltrexone include:

  • rash
  • itching
  • hives
  • fever
  • swollen lymph glands
  • painful sores in the mouth or around the eyes
  • swelling of the lips or tongue
  • chest pain
  • trouble breathing
  • stomach-area pain lasting more than a few days
  • dark urine
  • yellowing of the whites of your eyes
  • tiredness
  • eye pain
  • changes in vision
  • swelling or redness in or around the eye

Rare side effects of Bupropion/naltrexone include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.


Surprising Causes of Weight Gain See Slideshow

What Other Drugs Interact with Bupropion/Naltrexone?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Bupropion/Naltrexone?


Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Bupropion/naltrexone?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Bupropion/naltrexone?”


  • Monitor patients for suicidal ideation or behavior and unusual changes in behavior (see black box warning)
  • Discontinue therapy and do not restart if a seizure occurs while on therapy; use caution when prescribing to patients with predisposing risk factors for seizures
  • Not for administration to patients receiving long-term opioids, owing to naltrexone component (opioid antagonist); discontinue therapy if long-term opiate therapy required
  • Following therapy, patients may be more sensitive to opioids, even at lower doses
  • A patient should not attempt to overcome naltrexone opioid blockade by administering large amounts of exogenous opioids; may lead to a fatal overdose
  • Opioid-dependent patients, including those being treated for alcohol dependence, should be opioid-free (including tramadol) before therapy is initiated; opioid-free interval of a minimum of 7-10 days is recommended for patients previously dependent on short-acting opioids; patients transitioning from buprenorphine or methadone may need as long as 2 weeks
  • Blood pressure and pulse should be measured before starting therapy and should be monitored at regular intervals, particularly among patients with controlled hypertension prior to treatment
  • Discontinue therapy if symptoms or signs of acute hepatitis occur
  • Screen patients for a history of bipolar disorder and the presence of risk factors for bipolar disorder; therapy was not studied in patients receiving antidepressant medications patients with a history of bipolar disorder or recent hospitalization for psychiatric illness were excluded from clinical trials
  • The angle-closure attack may occur in patients with anatomically narrow angles that do not have a patent iridectomy
  • Measure blood glucose levels prior to and during therapy; patients who develop hypoglycemia after initiating Contrave therapy should adjust antidiabetic drug regimen
  • Use caution in patients with a history of tumor or infection of the brain or spine
  • Initiation of therapy in patients receiving linezolid or intravenous (IV) methylene blue
  • Use caution in hepatic impairment
  • May precipitate a manic, mixed, or hypomanic episode; risk higher in patients with bipolar disorders or have risk factors for bipolar disorder, including a family history of bipolar disorder, suicide, or depression; not FDA approved for bipolar depression
  • Some patients who stopped smoking reported to have experienced symptoms of nicotine withdrawal, including depressed mood; depression, rarely including suicidal ideation, reported in smokers undergoing a smoking cessation attempt without medication; however, some of these adverse events occurred in patients taking bupropion who continued to smoke
  • Neuropsychiatric adverse events reported in patients without and with pre-existing psychiatric disease; some patients experienced worsening of their psychiatric illnesses; observe patients for the occurrence of neuropsychiatric adverse events; the patient should stop therapy and contact healthcare provider immediately if agitation, depressed mood, or changes in behavior or thinking that are not typical for the patient are observed, or if the patient develops suicidal ideation or suicidal behavior; symptoms may persist after discontinuation of therapy; in some cases; monitoring and supportive care should be provided until symptoms resolve

Pregnancy and Lactation

  • Weight loss offers no benefit to a pregnant patient and may cause fetal harm; when a pregnancy is recognized, advise pregnant patient of risk to the fetus, and discontinue therapy; available pharmacovigilance data and data from clinical trials with individual components of combination drug use in pregnant patients have not demonstrated a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes
  • Bupropion
    • Data from epidemiological studies of pregnant patients exposed to bupropion in the first trimester have not identified an increased risk of congenital malformations overall
    • When bupropion was administered to pregnant rats during organogenesis, there was no evidence of fetal malformations at doses up to approximately 20 times the maximum recommended human dose (MRHD) of 360 mg/day
    • When given to pregnant rabbits during organogenesis, non-dose–related increases in the incidence of fetal malformations, and skeletal variations were observed at doses approximately twice the MRHD and greater; decreased fetal weights were seen at doses 5 times MRHD and greater
  • Naltrexone
    • Limited case report data of pregnant patients exposed to naltrexone in the first trimester have not identified an increased risk of congenital malformations overall; daily oral administration of naltrexone during the period of organogenesis has been shown to increase the incidence of early fetal loss in rats and rabbits at doses above 15 times and 60 times MRHD of 32 mg/day respectively
    • There was no evidence of fetal malformations in rats and rabbits at doses up to approximately 100 and 200 times the MHRD, respectively
    • Appropriate weight gain based on pre-pregnancy weight is currently recommended for all pregnant patients, including those who are already overweight or obese, due to obligatory weight gain that occurs in maternal tissues during pregnancy 
  • Lactation
    • Data from published literature report the presence of bupropion and its metabolites in human milk
    • Limited data from postmarketing reports with bupropion use during lactation have not identified a clear association of adverse effects on a breastfed infant
    • Naltrexone and its major metabolite, 6 β-naltrexol, are present in human milk; there are no data on bupropion, naltrexone, or their metabolites on milk production; the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for therapy and any potential adverse effects on the breastfed infant from drug combination or mother’s underlying condition
Medscape. Bupropion/Naltrexone


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