When Does Qsymia Start Working and What are the Side Effects?

Published September 30th, 2020 by Bridget Reed
Fact Checked by
Chris Riley
Medically Reviewed:
Dr. Angel Rivera
Updated Date: Mar 17th, 2022

What is Qsymia | Used to Treat | When Does it Start Working | Cost | Side Effects

It’s no secret that obesity is an epidemic in the United States, with approximately 42.2 percent of American adults classified as obese according to the Centers for Disease Prevention and Control

The percentage of American adults classified as obese by their body mass index has risen by nearly 12 percent since 1999-2000, and the total continues to grow daily as a result of sedentary lifestyles and high calorie, high fat Western diets that are heavy in processed foods.

Obesity-related medical conditions cost approximately 147 billion dollars per year, and people who are obese pay approximately 1,429 dollars more per year in medical costs compared to people who are at a normal weight.

There are many weight related comorbidities that are linked to being overweight and obese, including dyslipidemia, type 2 diabetes mellitus, stroke, heart disease, high blood pressure, high cholesterol, and even some types of cancer.

Many Americans try to lose weight but find that they are unable to do so, and those who do lose weight often struggle to keep it off.

Prescription medications like Qsymia offer hope for people who are obese or who are overweight and have a weight-related medical condition, as the drug is designed to help these individuals lose weight when used in conjunction with a reduced-calorie diet, exercise plan, and behavioral changes. 

What is Qsymia

Qsymia is a prescription medication that contains two drugs, phentermine and an extended-release form of topiramate. Phentermine is an appetite suppressant medication that belongs to a class of drugs called sympathomimetic amines, and it can be habit forming.

Topiramate belongs to a class of drugs known as anticonvulsants.  Qsymia was approved by the U.S. Food and Drug Administration (FDA) in 2012 as a prescription medication to help obese and some overweight adults lose weight and keep it off.

The medication is designed to be used in conjunction with a physician-approved diet, physical activity, and behavioral/lifestyle changes plan in order to help patients lose weight and keep it off. 

What Conditions is Qsymia Used to Treat?

Qsymia is a prescription medication manufactured by Vivus, Inc. that helps obese adults and some overweight adults with weight-related medical conditions to lose weight and keep it off.

Patients must meet certain guidelines to qualify for Qsymia use, such as being classified as obese (having a BMI of 30 kg/m2 or greater) or being classified as overweight (a BMI of 27 kg/m2 or greater) with a coexisting weight-related medical condition.

Type 2 diabetes, high blood pressure, back pain, increased risk of heart attack, and high cholesterol are examples of weight-related medical conditions.

Qsymia has the potential to be abused because of the inclusion of phentermine in the medication, so it is not intended for patients who only have a small amount of weight to lose.

When Does Qsymia Start Working?

Qsymia is composed of two different active ingredients, phentermine and topiramate.

Phentermine begins to take effect immediately and works as an appetite suppressant, which helps patients control their hunger right away.

Topiramate is an extended-release drug that helps patients control their cravings for 24 hours by providing a feeling of fullness and potentially altering the taste of some foods.

However, Qsymia alone will not help you lose weight, even though the medication starts working immediately.

The medication must be used in conjunction with a reduced-calorie diet, behavioral changes, and an exercise plan in order to be effective.

The FDA prescribing information recommends that if a patient does not lose at least three percent of their initial body weight over the course of 12 weeks of treatment while taking Qsymia for chronic weight management, the medication should be given at a higher recommended dose or discontinued.

The target weight loss goal while using Qsymia will vary from person to person.

How Much Does Qsymia Cost?

The two primary ways of saving on the drug include purchasing through the manufacturer’s website and using a pharmacy discount card at local pharmacies that carry the medication.

Because Qsymia is relatively new to the market, it is still manufactured under the original patent issued to the manufacturer.

Therefore, no generic option exists for Qsymia, which drives up the price of the drug as a result of no competition.

The medication can be purchased with a prescription directly from the manufacturer for a flat fee of 98 dollars across all doses through a program called Qsymia Engage.

The program offers home delivery and free educational resources. Qsymia is not covered by most commercial insurance plans, Medicare, or Medicaid, and the cost of purchasing through the manufacturer’s website cannot be applied towards deductibles or for reimbursement.

However, it is possible to save even more on the cost of the medication by using a pharmacy discount card.

Regardless of what type of insurance you have, if any, pharmacy discount cards offer savings on all FDA-approved medications, including Qsymia.

Instead of paying 98 dollars a month when purchasing through Qsymia Engage, patients using a pharmacy discount card can purchase Qsymia for less than 70 dollars per month, saving patients nearly 30 dollars with each prescription.

Because of the risk of serious birth defects, only doctors and pharmacies trained in Qsymia’s distribution program, Qsymia REMS, should prescribe or dispense the medication.

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What are the Side Effects of Qsymia?

There are both serious and common side effects associated with Qsymia. Common side effects of Qsymia include:

  • Numbness or tingling in the hands, feet, arms, or face (paraesthesia)
  • Dizziness
  • Trouble sleeping
  • Changes in the way foods taste or loss of taste (dysgeusia)
  • Constipation
  • Dry mouth

Possible side effects of Qsymia that can be serious include:

  • Difficulties concentrating, remembering, or speaking
  • Metabolic acidosis, or increases of acid in the bloodstream, which may be evidenced by:
    • Changes in the heartbeat that are noticeable
    • Feeling tired
    • Loss of appetite
    • Difficulty thinking clearly
  • Mood changes, such as depression or mood problems
  • Trouble sleeping
  • Possible seizures when stopping use of the medication too quickly
  • Kidney stones
  • Hypoglycemia, or low blood sugar, in people with type 2 diabetes who take medications to treat their condition
  • Decreased sweating and increased body temperature or fever

Serious side effects of Qsymia that require immediate medical attention include:

  • Suicidal thoughts or actions
  • Birth defects in pregnant women. If you become pregnant while taking Qsymia, stop taking the medication immediately and notify your healthcare provider.
  • Serious eye problems that can result in permanent loss of vision, including:
    • Redness or blockage of fluid in the eye causing increased pressure in the eye
    • Sudden decrease in vision with or without eye pain
    • Angle closure glaucoma
  • Some heart problems, such as increases in heart rate while at rest that last more than a minute

Who Should Not Take Qsymia?

Qsymia can be dangerous when taken by certain people, as it can cause serious and potentially harmful side effects. People who should not take Qsymia include:

  • People taking medications called monoamine oxidase inhibitors (MAOIs) or people who have taken MAOIs in the past 14 days
  • People with glaucoma
  • Women who are pregnant, planning to become pregnant, or who become pregnant while taking Qsymia
  • People with thyroid problems, including hyperthyroidism
  • People who are allergic to topiramate, sympathomimetic amines like phentermine, or any of Qsymia’s ingredients.

Additionally, some drug interactions between phentermine/topiramate and antiepileptic drugs like valproic acid and zonisamide, amphetamines, and over the counter weight loss products. Always ensure you seek medical advice before starting even a low dose of Qsymia to prevent adverse events and unusual changes due to drug interactions. 

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