Contrave side effects explained: What to expect and how to avoid them

In this article:

• Common side effects
• Serious side effects
• Initial side effects
• How long do Contrave side effects last?
• What are the long-term side effects of Contrave?
• Who shouldn't take Contrave
• Warnings and interactions
• How to avoid Contrave side effects
• How to treat side effects

In this article

• Common side effects
• Serious side effects
• Initial side effects
• How long do Contrave side effects last?
• What are the long-term side effects of Contrave?
• Who shouldn't take Contrave
• Warnings and interactions
• How to avoid Contrave side effects
• How to treat side effects

Contrave (naltrexone/bupropion) extended-release tablet is a brand-name medication used for weight management along with a reduced-calorie diet and increased physical activity. Contrave reduces food intake by targeting two regions of the brain: the mesolimbic reward system and the hypothalamus. In these areas, Contrave regulates feelings of pleasure when eating to help control cravings and curb hunger. Although it’s effective, it has a higher risk of side effects than other weight loss medications.

Common side effects of Contrave

The most common side effects of Contrave are nausea, headache, and constipation. According to clinical trial data, 24% of patients receiving Contrave discontinued treatment because of an adverse event, as they could not tolerate the weight loss medicine.

Other side effects of Contrave include the following:

• Vomiting
• Dizziness
• Insomnia
• Dry mouth
• Diarrhea
• Increase in blood pressure
• Increase in heart rate
• Anxiety
• Hot flush
• Fatigue
• Tremor
• Abdominal pain
• Stomach virus
• Influenza
• Ringing in the ears
• Urinary tract infection
• Excessive sweating
• Irritability
• Altered taste
• Rash
• Muscle strain
• Heart palpitations

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Serious side effects of Contrave

Contrave has several serious side effects, including a boxed warning for suicidal thoughts and behaviors. Serious side effects of Contrave include the following:

• Neuropsychiatric disorders
• Homicidal ideation
• Suicidality
• Depression exacerbation
• Hypersensitivity reaction
• Stevens-Johnson syndrome (a serious disorder of the skin)
• Erythema multiforme (skin reaction)
• Anaphylaxis
• Liver toxicity
• Heart attack
• Severe high blood pressure
• Seizures
• Angle-closure glaucoma

Nausea

Nausea is the most common side effect of Contrave and happens to about one-third of people taking it. Clinical trial data show the most frequent side effect leading to discontinuation is nausea. Along with nausea, other gastrointestinal (GI) side effects are common with Contrave, such as vomiting. Generally, nausea and other GI side effects are temporary and resolve quickly. Drinking plenty of water and eating a small amount of food with Contrave (such as dry toast) can help manage GI side effects. If symptoms do not improve, it is best to consult with the healthcare team and decide if an over-the-counter (OTC) anti-nausea medication is appropriate.

RELATED: 28 nausea medications and remedies

Constipation

Constipation is the second most common side effect of Contrave and happens to about 19% of people taking it. Like the other GI side effects common with Contrave, constipation is generally temporary and resolves quickly. While taking Contrave, it is best to stay hydrated and drink plenty of water to help “get things moving” again, as water is important for digestion. If symptoms do not improve, it is best to consult your healthcare provider and decide whether an OTC constipation medicine is necessary. However, worsening constipation with severe abdominal pain could indicate a more serious health condition requiring immediate medical attention.

RELATED: 24 home remedies for constipation

Headache

Aside from GI side effects, a headache is the next most common side effect of Contrave and happens in about 18% of people. This side effect is typically short-term. While taking Contrave, it is best to stay hydrated and drink plenty of water, which can help manage this side effect. If headache symptoms do not improve or become more severe, seek medical attention, as this could be a sign of a more serious problem, such as a hypertensive event (dangerously high blood pressure).

Insomnia

Some people taking Contrave may have trouble falling asleep, staying asleep, or getting good quality sleep. Insomnia is another common side effect of Contrave and happens in about 9% of people. Taking Contrave around bedtime may increase the risk of this side effect. Some tips for avoiding or managing insomnia include taking the evening Contrave dose before dinner and practicing good sleep hygiene. If symptoms do not improve, it is best to consult with the healthcare team and decide whether an OTC or prescription sleep aid is appropriate.

RELATED: 21 ways to sleep better tonight

Contrave side effects first week: What to expect

People who start taking Contrave are more likely to experience side effects at the start of treatment. Side effects may be more noticeable during the first four weeks, since Contrave is started at a low dose and gradually increased to the standard dose over the course of one month. Gradually increasing the dose can help prevent or lessen the severity of side effects. The most common side effects of Contrave during the start of treatment are nausea, vomiting, and constipation.

How long do Contrave side effects last?

Generally, most side effects of Contrave are temporary and resolve quickly as the body adjusts to the new medication, like nausea and other GI side effects. However, if a side effect continues to be bothersome or becomes more severe, it’s best to consult with a healthcare provider for medical advice.

What are the long-term side effects of Contrave?

Once Contrave is stopped, related side effects should resolve. However, some possible disease-related concerns could persist, such as liver problems, kidney problems, or narrow-angle glaucoma.

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Contrave contraindications

Certain people should not take Contrave as it could cause serious harm. The groups of people who have contraindications to Contrave include those who:

• Have uncontrolled hypertension (high blood pressure)
• Have seizure disorder or a history of seizures
• Use other bupropion-containing products, including Aplenzin, Forfivo XL, Wellbutrin SR, and Wellbutrin XL
• Have bulimia or anorexia nervosa, which increases the risk of seizures
• Use opioids or are experiencing acute opioid withdrawal
• Are undergoing abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs
• Are taking monoamine oxidase inhibitors (MAOI); at least 14 days should elapse between discontinuation of MAOI and initiation of treatment with Contrave
• Have an allergy to or a history of allergic reactions to bupropion or naltrexone

Pregnancy and nursing

Medications for weight loss therapy are not recommended during pregnancy or for women who are breastfeeding. Due to the potential for fetal harm associated with weight loss during pregnancy, you should not take Contrave when pregnant.

Children

Contrave is not recommended for use in children. The Food and Drug Administration (FDA) has not approved the use of Contrave for anyone under 18. 

Contrave warnings

Contrave has a boxed warning, the most severe type of warning mandated by the FDA, for suicidal thoughts and behavior. This risk should be considered and discussed with the provider before starting therapy with Contrave. The Suicide and Crisis Lifeline provides support 24/7 via 9-8-8, a toll-free hotline.

Some health conditions may get worse or cause serious side effects in people taking Contrave, so treatment will require more careful monitoring in older adults and people with any of the following conditions:

• Kidney or liver problems
• Bipolar disorder
• Diabetes mellitus
• Cardiovascular disease
• Narrow-angle glaucoma
• Psychiatric disorders

Overdose

Taking too much Contrave can lead to an overdose and result in serious problems, including seizures, convulsions, coma, respiratory failure, and death. Immediate emergency medical care is required if an overdose is suspected. Other symptoms of a Contrave overdose include:

• Racing heart
• Loss of consciousness
• Hallucinations
• Irregular heartbeat
• Hyperactive reflexes
• Stiff or rigid muscles

The maximum dosage of Contrave is four tablets a day. Each tablet contains 8 mg of naltrexone hydrochloride and 90 mg of bupropion hydrochloride.

Contrave interactions

Taking Contrave with certain drugs may cause a dangerous drug interaction. Contrave should not be taken with or used with caution in the following:

• Monoamine oxidase inhibitors (MAOIs): Examples include isocarboxazid, phenelzine, transdermal selegiline, and tranylcypromine, as they can increase the risk for hypertensive reactions.
• Drugs that are metabolized by the CYP2D6 isozyme: Examples include certain antidepressants (SSRIs and many tricyclics), antipsychotics (such as haloperidol, risperidone, and thioridazine), beta blockers (such as metoprolol), and Type 1C antiarrhythmics (such as propafenone and flecainide).
• Opioid analgesics: People taking Contrave may not fully benefit from treatment with opioid-containing medicines.
• Dopaminergic drugs: Medications such as levodopa and amantadine can increase the chance of CNS toxicity.
• Alcohol and caffeine: Alcohol and caffeine may increase the adverse effects, including a greater chance of seizures, and alcohol tolerance may decrease during treatment.
• Drugs that lower the seizure threshold: Examples include antipsychotics, antidepressants, theophylline, or systemic corticosteroids.

How to avoid Contrave side effects

While some Contrave side effects are common, there are tips for avoiding and minimizing side effects:

1. Take Contrave as directed: Contrave dosing should be increased slowly over the course of one month according to a specific schedule. Take tablets whole and do not cut, chew, or crush them. A helpful dosing tip is to take the morning dose with breakfast and the evening dose before dinner.
2. Tell your healthcare provider about all your medical conditions and medications you’re taking: You can prevent unnecessary side effects of Contrave by letting your healthcare provider know about all of your medical conditions and any medications you’re taking. This includes prescription drugs, OTC drugs, and dietary supplements. Doing so can prevent dangerous drug interactions that may increase adverse events.
3. Drink plenty of water: Staying hydrated can help with common side effects like nausea, headache, and constipation.
4. Do not take Contrave with high-fat meals: Taking Contrave with high-fat meals may increase the risk of seizures. Other foods to avoid on Contrave include processed foods, caffeine, and foods high in refined sugar.
5. Monitor body weight loss: Contrave can usually be discontinued once you’ve achieved a weight loss of <4% to 5% of baseline after three months. Once you stop taking Contrave, you should continue a healthy diet and regular physical activity to manage your weight.

How to treat the side effects of Contrave

Most of the side effects of Contrave are temporary and resolve quickly as the body adjusts to the new medication. However, there are some tips to help treat side effects and lessen their severity if they are bothersome. If a side effect continues and becomes more severe, it’s best to consult with your healthcare provider.

Nausea treatment

To help with nausea, it’s important to drink plenty of water and eat a small amount of food with Contrave (such as dry toast). If symptoms do not improve, it is best to consult with a healthcare provider and decide whether an OTC anti-nausea medication (such as Dramamine or Pepto Bismol) is appropriate.

Constipation treatment

As another common GI side effect, drinking plenty of water and staying hydrated can help treat constipation associated with Contrave, as water is vital for digestion. If symptoms do not improve, it is best to consult a provider and decide whether an OTC constipation medicine (such as Senna or Dulcolax) is necessary.

Headache treatment

Some headaches can be successfully treated with OTC pain reliever medications such as Tylenol (acetaminophen), Advil or Motrin (ibuprofen), or Aleve (naproxen). Similar to the treatment of some GI side effects, staying hydrated and drinking plenty of water can also help treat headaches. Some other useful techniques include resting in a darkened room or placing a cold pack on the forehead.

RELATED: 8 types of headaches and how to treat them

Insomnia treatment

Trouble sleeping, like difficulty falling asleep and staying asleep or getting good quality sleep, can be a bothersome side effect of Contrave. Taking the evening dose of Contrave before dinner and practicing good sleep hygiene can help treat insomnia. If symptoms do not improve, it is best to consult a healthcare provider and decide whether an OTC sleep aid (such as melatonin or Unisom) or a prescription sleep aid is appropriate.

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Bottom line

Contrave is generally safe when used as directed, but side effects can occur. If they become bothersome, talk to your healthcare provider. They may recommend a Contrave alternative that may be more effective, and using your free SingleCare prescription discount card can help you save. 

RELATED: How to save on Contrave