(RxWiki News) The second weight loss drug in a month has been approved by the US Food and Drug Administration today. Qsymia can now be prescribed for obese and some overweight adults.
Qsymia, which is a combination of two previously-approved drugs called phentermine and topiramate extended-release, should be used with a reduced-calorie diet and exercise, according to the FDA press release.
"Talk to your doctor about safe weight loss plans."
The FDA approved Qsymia for those considered obese or those who are overweight and have at least one weight-related condition, such as type 2 diabetes, high blood pressure or cholesterol.
"Obese" is defined as having a body mass index (BMI), or a ratio of a person's weight to height in metric measurements, of 30. "Overweight" means having a BMI of at least 27.
The two components of Qsymia do different things. One component, phentermine, has already been approved by the FDA for short-term weight loss in severely overweight people who are also eating a reduced-calorie diet and exercising.
The other component, topiramate, is typically used to treat epileptic seizures and migraines.
Because topiramate has been shown to cause birth defects such as cleft palates when used during a woman's first trimester of pregnancy, Qsymia also cannot be used by pregnant women or women trying to get pregnant.
Like other drugs that are not safe for pregnant women, any woman capable of conceiving should test negative for pregnancy before starting to take Qsymia.
She should then use effective contraception and take a pregnancy test once a month to be sure she does not become pregnant while taking the drug.
Because of the dangers to a developing baby if a pregnant woman takes Qsymia, the drug will only be dispensed at certified pharmacies.
Pharmacists will provide women with information about the risks of taking the drug during pregnancy and about the precautions she should take to ensure she does not get pregnant. She should immediately discontinue use of Qsymia if she does become pregnant.
Also, patients with glaucoma or hyperthyroidism should not take Qsymia.
Those who have heart conditions or are at a higher risk for heart disease, heart attack or stroke may want to be cautious in taking Qsymia because it can increase a person's heart rate.
Researchers do not have information on whether it can adversely affect someone at high risk for heart problems or stroke. Part of the requirements for FDA approval are that the manufacturer, Vivus Inc., conducts long-term trials on cardiovascular effects of the medication.
Qsymia's safety and effectiveness were tested in two drug trials involving approximately 3,700 obese and overweight participants.
All the participants in the trials were also eating a reduced-calorie diet and were exercising regularly.
The trial participants who took the recommended dose (7.5 mg of phentermine and 46 mg of topiramate extended-release) of Qsymia over one year had a 6.7 percent reduction in weight compared to those taking the placebo (fake pill). About 62 percent of these participants lost at least 5 percent of their body weight.
Those who took the highest dose (15 mg phentermine and 92 mg of topiramate extended-release) of Qsymia for one year lost 8.9 percent of their weight compared to the placebo group. About 69 percent lost at least 5 percent of their weight.
Among patients taking the placebo, only 20 percent in this group lost 5 percent of their body weight or more during the one-year trials.
The FDA recommends that Qsymia only be prescribed initially for three months. If a person has not lost at least five percent of their body weight in this time, they should discontinue the drug because it's unlikely to work for them.
Common side effects of Qsymia include tingling sensations in the hands and feet (like when a limb "falls asleep"), dizziness, insomnia, constipation, a dry mouth and a change in taste in the mouth.