Contrave Vs. Mounjaro: Drug Comparison

Contrave^® (naltrexone hydrochloride and bupropion hydrochloride) is a prescription medication used for weight management in adults, combining two active ingredients: naltrexone, which affects the brain's reward system, and bupropion, which influences appetite and cravings. It works by targeting the hypothalamus to reduce hunger and the mesolimbic reward system (a pathway in the brain that plays a key role in regulating feelings of pleasure, motivation, and reinforcement) to curb food cravings. Contrave is FDA-approved for chronic weight management. Common side effects include nausea, constipation, headache, and insomnia, while drug interactions can occur with MAO inhibitors, opioid pain medications, and drugs that lower the seizure threshold. Contrave carries a boxed warning for an increased risk of suicidal thoughts and behaviors, particularly in young adults, due to its bupropion component.

Mounjaro^® (tirzepatide) is an injectable medication used to treat type 2 diabetes by improving blood sugar control and promoting weight loss. It functions by activating two receptors, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which enhance insulin secretion and slow gastric emptying. Mounjaro is administered once weekly, with dose adjustments made based on the patient's response. Common side effects include nausea, diarrhea, and decreased appetite. It should be used with caution in individuals with a history of thyroid cancer or multiple endocrine neoplasia syndrome type 2​.

Naltrexone: opioid antagonist

Bupropion: aminoketone antidepressant

Glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist

Contrave (naltrexone hydrochloride and bupropion hydrochloride) is indicated:

• As an adjunct to a reduced-calorie diet and increased physical activity for chronic weight management in adults with an initial body mass index (BMI) of:

  • 30 kg/m² or greater (obese)

  • 27 kg/m² or greater (overweight) in the presence of at least one weight-related comorbidity (e.g., hypertension, type 2 diabetes mellitus, or dyslipidemia)

Mounjaro (tirzepatide) is indicated:

• As an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus

• Typically taken orally twice daily

• Comes as 8 mg/90 mg extended-release tablets

• Typically taken as an injection once weekly

• Comes in 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg per 0.5 mL single-dose pens or single-dose vials

Most common adverse reactions (greater than or equal to 5%):

• Nausea

• Constipation

• Headache

• Vomiting

• Dizziness

• Insomnia

• Dry mouth

• Diarrhea

The most common adverse reactions, reported in ≥5% of patients treated with Mounjaro are:

• Nausea

• Diarrhea

• Decreased appetite

• Vomiting

• Constipation

• Indigestion

• Abdominal pain

• Uncontrolled hypertension

• Seizure disorders, anorexia nervosa or bulimia, or undergoing abrupt discontinuation of alcohol, benzodiazepines, barbiturates, and antiepileptic drugs

• Use of other bupropion-containing products

• Chronic opioid use

• During or within 14 days of taking monoamine oxidase inhibitors (MAOI)

• Known allergy to any of the ingredients in Contrave

• Drug interactions: MAOIs, antidepressants (e.g., selective serotonin reuptake inhibitors and many tricyclics), antipsychotics (e.g., haloperidol, risperidone, and thioridazine), beta-blockers (e.g., metoprolol), type 1C antiarrhythmics (e.g., propafenone and flecainide), digoxin, CYP2B6 inhibitors (e.g., ticlopidine or clopidogrel), CYP2B6 inducers (e.g., ritonavir, lopinavir, efavirenz, carbamazepine, phenobarbital, and phenytoin), drugs that lower seizure threshold, dopaminergic drugs (levodopa and amantadine)

• Personal or family history of medullary thyroid carcinoma or in patients with multiple endocrine neoplasia syndrome type 2

• Known serious hypersensitivity to tirzepatide or any of the excipients in Mounjaro

• Drug interactions: Mounjaro delays gastric emptying and has the potential to impact the absorption of concomitantly administered oral medications

• Suicidal behavior and ideation

• Neuropsychiatric adverse events during smoking cessation

• Risk of seizure may be minimized by adhering to the recommended dosing schedule and avoiding coadministration with high-fat meal

• Increase in blood pressure and heart rate

• Liver toxicity

• Angle-closure glaucoma

• Use of antidiabetic medications: Weight loss may cause hypoglycemia

• Pregnancy: Weight loss during pregnancy may cause fetal harm. Discontinue when a pregnancy is recognized

• Pancreatitis

• Low blood sugar with concomitant use of insulin secretagogues or insulin

• Hypersensitivity reactions

• Acute kidney injury

• Severe gastrointestinal disease

• Diabetic retinopathy complications in patients with a history of diabetic retinopathy

• Acute gallbladder disease

• Pregnancy: Based on animal study, may cause fetal harm

• Females of reproductive potential: Females using oral contraceptives should consider switching to a non-oral contraceptive method or add a barrier method of contraception for 4 weeks after initiation and for 4 weeks after each dose escalation

WARNING: SUICIDAL THOUGHTS AND BEHAVIORS

Increased risk of suicidal thinking and behavior in children, adolescents, and young adults taking antidepressants for major depressive disorder and other psychiatric disorders. Monitor for worsening and emergence of suicidal thoughts and behaviors.

Contrave has not been studied in pediatric patients.

WARNING: RISK OF THYROID C-CELL TUMORS

Tirzepatide causes thyroid C-cell tumors in rats. It is unknown whether Mounjaro causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as the human relevance of tirzepatide-induced rodent thyroid C-cell tumors has not been determined.

Mounjaro is contraindicated in patients with a personal or family history of MTC or in patients with multiple endocrine neoplasia syndrome type 2 (MEN 2). Counsel patients regarding the potential risk of MTC and symptoms of thyroid tumors.

*This information is from the label for brand name Contrave^®. See the Full Prescribing Information for more complete information. Naltrexone and bupropion, the active ingredients in Contrave, may also be the active ingredients in other medications, and this information may not be accurate for all medications that include the active ingredients naltrexone and bupropion.

*This information is from the label for brand name Mounjaro. See the Full Prescribing Information for more complete information. Tirzepatide, the active ingredient in Mounjaro, may also be the active ingredient in other medications, and this information may not be accurate for all medications that include the active ingredient tirzepatide.