How Does Qsymia work for weight loss?
Qsymia is a combination of two drugs, phentermine and extended-released topiramate and works in two ways: phentermine acts to lower the appetite and reduce food intake and topiramate can help you feel more full.
- It is thought Qsymia may increase the activity of the neurotransmitter GABA (γ-aminobutyric acid), which is a chemical messenger in your brain. This can suppress your appetite and make you feel more full. Qsymia may also alter the tastes of certain foods.
- Qsymia will start to work right after you take it and it is used in addition to a reduced calorie diet and increased physical exercise.
- It is given as a long-term, once daily oral capsule to help suppress appetite throughout the day.
Phentermine is classified as a sympathomimetic amine, central nervous system stimulant and appetite suppressant (anorexiant) and and acts on the brain to suppress your appetite. Topiramate is an anticonvulsant (seizure medicine) used to treat epilepsy and for migraine headache prevention.
The exact mechanism of action of Qsymia is not fully known.
Learn more: Weight Loss and Diet Pills: What are My Options?
Who can use Qsymia?
Qsymia (phentermine and topiramate ER) is used for chronic weight management in:
- Adults: Those who are obese (BMI of 30 kg/m2 or higher) OR those who are overweight (BMI of at least 27 kg/m2) and also have at least one weight-related condition, such as type 2 diabetes, high blood pressure, or high cholesterol.
- Children: aged 12 years and older with a body mass index (BMI) in the 95th percentile or greater (when standardized for age and sex). Your child's pediatrician can determine their BMI.
The manufacturer provides a BMI chart using patient height and weight in the product label. It is manufactured by Vivus Pharmaceuticals and was first approved in 2012.
The Qsymia dose is taken once daily in morning with or without food; you should avoid an evening dose as it may interfere with sleep.
Your doctor will slowly increase your dose over a 28-day period and will evaluate your weight loss after 12 to 24 weeks of treatment with Qsymia, depending upon your final dose.
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How well does Qsymia work for weight loss?
In 56-week long clinical trials, patients lost on average 14.5 kg (32 lb) using Qsymia 15 / 92 mg plus diet and exercise, and about 5 inches off of their waist. Patients using a placebo (an inactive pill with no medicine) lost 2.7 kg (6 lb) and 1.7 inches.
Related: Does topiramate cause weight loss?
Is Qsymia a controlled substance?
- Yes, Qsymia is a C-IV controlled substance because it contains phentermine and can be abused or lead to drug dependence.
- Never give Qsymia to anyone else because it harm them or lead to death. Keep this medicine in a safe place to protect it from theft or accidental exposure to pets or other people.
- Selling or giving away this medicine is against the law.
This is not all the information you need to know about Qsymia (phentermine and topiramate ER) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.
References
- Qsymia (phentermine and topiramate extended-release capsules). Vivus. Campbell, CA. Accessed May 22, 2023 at https://qsymia.com/patient/include/media/pdf/prescribing-information.pdf
- Centers for Disease Control and Prevention (CDC). Overweight and Obesity. Accessed May 22, 2023 at https://www.cdc.gov/obesity/
- How Qsymia works. Vivus.com. Accessed May 22, 2023 at https://hcp.qsymia.com/how-qsymia-works/l
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Drug information
- Qsymia Information for Consumers
- Qsymia prescribing info & package insert (for Health Professionals)
- Side Effects of Qsymia (detailed)
- Qsymia user reviews (567)
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