This May I critiqued the expected approval of the first new weight loss drugs in thirteen years . And yes, it's happened. The FDA approved Arena Pharmaceutical's Belviq late last month, and Vivus Inc.'s Qsymia yesterday.

The one surprise? Vivus Inc. previously called their drug Qnexa. They changed it to Qsymia this month, apparently due to concerns over confusion with other drug names.

The New York Times explains the drug's origins:

Qsymia is a combination of two existing drugs, one of which is phentermine, an appetite suppressant that is the component of the fen-phen combination that remained on the market. The other is topiramate, an epilepsy and migraine drug.

Together these drugs can make you desire food less (that's the stimulant phentermine at work, think Adderall) and feel more full.

As I mentioned in my past post , weight loss drugs carry with them an unsavory history. Physician Danielle Ofri writes in the Times:

Fen-phen, ephedra, sibutramine and phenylpropanolamine all had to be pulled from the market for safety concerns. A drug popular in Europe, rimonabant, was denied approval in the United States because of side effects. The lone prescription drug currently available in America for weight loss, orlistat, offers only minor weight loss with the trade-off of major stomach problems in the form of oily, greasy stools.

Qsymia too carries considerable side effects, the most troubling being birth defects. Pregnant women can't be prescribed the pill, women of child-bearing age who use it will have to use contraception, and it will only be offered through approved mail-order pharmacies.

Other possible side effects include mood disturbances, trouble thinking and increased heart rate (But at least you'll be thinner?! Eesh).

While Belviq promises only a 3-4% loss in body weight, studies suggest people on Qsymia lose an average of 8-10% of their weight over a year, more than any other weight loss drug.

However, industry analysts believe Qsymia's side effects may steer consumers towards Belviq. Bloomberg Businessweek reports:

The warnings in Vivus's packaging may benefit Arena's Belviq in the marketplace, said Atsushi Seki, a health- care analyst at Barclays Plc in Tokyo. The market for obesity treatments will probably reach $6 billion a year, and Barclays expects annual sales of Belviq to peak at $1.5 billion, he said.

As of this morning Vivus stock had jumped eleven percent to $29.39.

Vivus hopes to have their drug covered by insurance companies within a year, though they've declined to state its price.

[via NPR, The New York Times, and Bloomberg Businessweek]

photo: inquisitr.com

This post was originally published on Smartplanet.com