Posted: Jul 18, 2012 12:51 AM
July 17, 2012 -- For the second time in less than a month, the FDA has approved a new prescription weight loss drug.
Qsymia, developed by California-based Vivus Inc., combines two already prescribed medications -- the stimulant phentermine and the anti-seizure drug Topamax (topiramate) -- in a controlled-release pill that is taken once a day.
Last February, an FDA advisory panel overwhelmingly voted to recommend the drug -- formerly called Qnexa -- for promoting weight loss in people who are obese, with the exception of pregnant women.
"Obesity is one of the biggest problems we are facing in health care, and we need more tools to help people lose weight," says diabetes specialist Abraham Thomas, MD, who served on the FDA advisory panel. "But these drugs are not a replacement for lifestyle changes."
Qsymia's approval came as an addition to a reduced-calorie diet and exercise.
It is approved for use in adults with a body mass index (BMI) of 30 or above, which is considered obese, or a BMI of 27 or greater (overweight) with at least one weight-related condition, such as high blood pressure, type 2 diabetes, or high cholesterol.
Just as with Belviq (lorcaserin), the weight loss drug that was approved late last month, federal officials will require post-marketing studies to look for evidence of increased heart disease or stroke risk in people who take Qsymia.
Women who might become pregnant are also being advised to use effective birth control while on the drug, and monthly pregnancy tests are also being recommended, along with an initial negative pregnancy test before starting the medication.
Fetal exposure to topiramate has been linked to an increased risk for cleft lip, with or without cleft palate.
Qsymia also must not be used in people with glaucoma or hyperthyroidism. Use of the drug in people with recent or unstable heart disease or stroke is not recommended. Patients are also recommended to have regular monitoring of heart rate when starting the drug or increasing the dose.
The FDA approved Qsymia with a Risk Evaluation and Mitigation Strategy (REMS), designed to educate prescribers and their patients about the increased risk of birth defects associated with first trimester exposure to the drug, along with the need to avoid pregnancy while taking it.
And the drug will only be dispensed through specially certified pharmacies.
The FDA rejected Vivus' first petition for the drug's approval in October 2010, citing, among other things, concerns that the medication increased the risk of heart attack and stroke in some patients.
That same month, the agency also failed to approve Belviq and forced the removal of the weight loss drug Meridia from the market because of concerns of an increased risk of heart disease and stroke among users.
The approval of two new drugs in just a few weeks signals recognition by federal officials that new weapons are needed in the battle against obesity, says W. Timothy Garvey, who chairs the department of nutrition sciences the University of Alabama at Birmingham.
Garvey was a lead researcher in the Qsymia studies.
Patients in those trials who took Qsymia and made lifestyle changes lost an average of about 10% of their body weight after one year on the drug, compared to a 2% weight loss in people who took placebo pills.
Although this loss is considered modest, it was still about twice as much as was reported in trials of Belviq and some other weight loss drugs.
Side effects included constipation, dry mouth, and tingling in the fingers and toes, but Garvey says there was no evidence of an increase in heart disease or stroke risk associated with the drug's use.
He adds that people with diabetes or those at high risk for developing diabetes may benefit most from taking the drug.
In the company-sponsored studies, these patients showed improvements in blood sugar control, along with weight loss.
"We haven't had a new drug for obesity in over a decade," Garvey says. "These drugs help fill this void."
But critics counter that people who take the drugs may be risking serious harm for little benefit.
"These drugs don't work all that well and they are dangerous," says Sidney Wolfe, PhD, who is director of health research for the consumer group Public Citizen.
"In the case of (Qsymia), this is the second time that a company has sought to combine (the stimulant) phentermine with another drug," he tells WebMD. "The first time was Fen-Phen."
At the height of its popularity in the 1996, 18 million prescriptions were written for the combination diet drug fenfluramine and phentermine, or Fen-phen.
The drug was taken off the market after being linked to potentially serious heart valve problems in as many as 1 in 3 users.
Fenfluramine and not phentermine was determined to be the cause of the heart valve issues.
"These (new) drugs were approved because patients and doctors are desperate," he says.
The medication will be available by the fourth quarter of this year, but the price is not being released yet, according to media reports.