Qsymia Vs. Wegovy: Drug Comparison

Qsymia^® (phentermine and topiramate) is a prescription medication used for chronic weight management in adults with obesity or overweight with at least one weight-related condition, such as hypertension, type 2 diabetes, or high cholesterol. It combines two active ingredients: phentermine, an appetite suppressant, and topiramate, which induces a feeling of fullness and reduces appetite. Qsymia is intended to be used alongside a reduced-calorie diet and increased physical activity. Common side effects include dry mouth, constipation, and tingling sensations in the hands and feet. It should be used with caution due to potential risks such as mood changes, increased heart rate, and birth defects if taken during pregnancy.

Wegovy^® (semaglutide) is an injectable medication approved for chronic weight management in adults with obesity or overweight with at least one weight-related condition, such as hypertension, type 2 diabetes, or high cholesterol. It works by mimicking the hormone glucagon-like peptide-1 (GLP-1), which regulates appetite and food intake, leading to reduced calorie consumption and significant weight loss. Wegovy is administered once weekly and is intended to be used in conjunction with a reduced-calorie diet and increased physical activity. Common side effects include nausea, diarrhea, vomiting, and constipation. It should be used with caution in patients with a history of pancreatitis and is not recommended for use in pregnant or breastfeeding individuals​.

Phentermine: sympathomimetic amine anorectic

Topiramate: anticonvulsant

Glucagon-like peptide-1 (GLP-1) receptor agonist

Qsymia (phentermine and topiramate) 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) or

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

  • Pediatric patients aged 12 years and older with BMI in the 95th percentile or greater standardized for age and sex

Wegovy (semaglutide) is indicated in combination with a reduced calorie diet and increased physical activity:

• To reduce the risk of major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal stroke) in adults with established cardiovascular disease and either obesity or overweight

• To reduce excess body weight and maintain weight reduction long term in:

  • Adults and pediatric patients aged 12 years and older with obesity

  • Adults with overweight in the presence of at least one weight-related comorbid condition

• Typically taken orally once daily

• Comes in 3.75 mg/23 mg, 7.5 mg/46 mg, 11.25 mg/69 mg, and 15 mg/92 mg extended-release capsules

• Typically taken as an injection once weekly

• Comes in single-dose pens that deliver 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, or 2.4 mg per injection

Most common adverse reactions in adults (incidence ≥5% and at least 1.5 times placebo) are:

• Tingling sensation

• Dizziness

• Altered taste

• Insomnia

• Constipation

• Dry mouth

Most common adverse reactions in pediatric patients aged 12 years and older (incidence ≥4% and greater than placebo) are:

• Depression

• Dizziness

• Joint pain

• Fever

• Influenza

• Ligament sprain

Most common adverse reactions (incidence ≥5%) in adults or pediatric patients aged 12 years and older are:

• Nausea

• Diarrhea

• Vomiting

• Constipation

• Abdominal pain

• Headache

• Fatigue

• Indigestion

• Dizziness

• Abdominal distension

• Belching

• Low blood sugar in patients with type 2 diabetes

• Flatulence

• Inflammation of the digestive system

• Gastroesophageal reflux disease (heartburn)

• Inflammation of the nasal cavities and back of the throat

• Pregnancy

• Glaucoma

• Hyperthyroidism

• Taking or within 14 days of stopping monoamine oxidase inhibitors

• Known hypersensitivity to any component of Qsymia or idiosyncrasy to sympathomimetic amines

• Drug interactions: Oral contraceptives, central nervous system (CNS) depressants including alcohol, non-potassium sparing diuretics

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

• Known hypersensitivity to semaglutide or any of the excipients in Wegovy

• Drug interactions: Wegovy delays gastric emptying. May impact absorption of concomitantly administered oral medications

• Embryo-fetal toxicity: Can cause fetal harm

• Increase in heart rate

• Suicidal behavior and ideation

• Risk of ophthalmologic adverse reactions

• Mood and sleep disorders

• Cognitive impairment: May cause disturbances in attention or memory, or speech/language problems

• Slowing of linear growth

• Metabolic acidosis

• Decrease in renal function

• Serious skin reactions

• Breastfeeding: Breastfeeding not recommended

• Acute pancreatitis

• Acute gallbladder disease

• Low blood sugar: Concomitant use with insulin or an insulin secretagogue may increase the risk of low blood sugar, including severe low blood sugar

• Acute kidney injury

• Hypersensitivity reactions

• Diabetic retinopathy complications in patients with type 2 diabetes

• Heart rate increase

• Suicidal behavior and ideation

• Pregnancy: May cause fetal harm. When pregnancy is recognized, discontinue Wegovy

• Females and males of reproductive potential: Discontinue Wegovy at least 2 months before a planned pregnancy because of the long half-life of semaglutide

WARNING: RISK OF THYROID C-CELL TUMORS

In rodents, semaglutide causes thyroid C-cell tumors at clinically relevant exposures. It is unknown whether Wegovy causes thyroid C-cell tumors, including medullary thyroid carcinoma (MTC), in humans as the human relevance of semaglutide-induced rodent thyroid C-cell tumors has not been determined.

Wegovy 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 Qsymia^®. See the Full Prescribing Information for more complete information.

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