Does naltrexone cause weight gain?
Key Points
- Weight gain is not a common side effect with oral naltrexone treatment. Naltrexone is approved to help promote weight loss when used in combination with bupropion (brand name: Contrave).
- Naltrexone is known to frequently cause stomach side effects like nausea and vomiting (10% or more of patients), stomach pain or cramping, and loss of appetite which could contribute to weight loss. These side effects may lessen over time.
- Oral naltrexone has been reported by the manufacturer to cause both weight gain and increased appetite, but these are not frequent adverse events.
Naltrexone when combined with bupropion (brand name: Contrave) is used to help with weight loss. Contrave is an extended-release form of two FDA-approved drugs, oral naltrexone tablets and oral bupropion (Wellbutrin SR).
Contrave is used in obese or overweight adults with at least one weight-related condition such as high blood pressure or type 2 diabetes. It is used in addition to diet and exercise. In clinical trials, 36% to 48% of patients taking Contrave lost at least 5% of body weight.
Naltrexone is an opioid antagonist approved to treat alcohol or opioid dependence (following detoxification) along with group counseling. Bupropion is classified as an antidepressant and is used to treat depression, seasonal affective disorder and as an aid to quit smoking.
Learn more: FDA Approved Weight Loss Drugs - Can They Help You?
References
- Naltrexone prescribing information. Major Pharmaceuticals. Last updated May 1, 2020. Accessed April 6, 2021 at https://www.drugs.com/pro/naltrexone.html
- Contrave (bupropion and naltrexone) prescribing information. Currax Pharmaceuticals. Last updated March 1, 2021. Accessed April 6, 2021 at https://www.drugs.com/pro/contrave.html
Read next
What is low dose naltrexone (LDN)?
Low dose naltrexone means taking a dose of naltrexone that is up to one-tenth, or 10%, of the dose that is usually taken for opioid addiction. A low dose of naltrexone is approximately 4.5mg of naltrexone a day compared with the usual dosage of naltrexone for opioid addiction which is 50mg to 100mg a day. Continue reading
What happens if you drink alcohol while taking naltrexone?
Naltrexone blocks the feelings of intoxication (the “buzz”) from alcohol when you drink it. This allows people with alcohol use disorder to lessen their drinking behaviors enough to stay in treatment, avoid relapses, and take their medication. Over time, cravings for alcohol will decrease. However, naltrexone will not prevent you from becoming impaired while drinking alcohol. Do not use naltrexone so that you can drive or perform other activities under the influence of alcohol. Continue reading
What to avoid when taking naltrexone?
Do NOT take opiates, including heroin or other prescription or illegal opiates while using naltrexone. Taking opiates with naltrexone increases your risk for an overdose, coma and death. Do not use naltrexone if you are dependent on opioids or if you are experiencing opioid withdrawal symptoms. Naltrexone should not be used before you complete a medically-supervised opioid withdrawal lasting at least 7 to 14 days. Continue reading
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