The FDA advisory committee has voted against approving Qnexa, one of the first new diet drugs to be reviewed by FDA in more than a decade. The decision to reject the drug due to lack of data on its safety reflected FDA’s concerns for potential health risks associated with the new wave of diet pills.

The FDA’s Endocrinologic and Metabolic Drugs Advisory Committee voted 10 to 6 against recommending the drug which is a combination of existing drugs phentermine and topiramate.

In a clinical study, side effects of Vivu’s Qnexa included increased heart rate, paresthesia, dry mouth, constipation, upper respiratory tract infection and headache. Although Qnexa was effective at weight-loss with patients losing between 13 to 15 percent of their body weight, the agency concluded that the safety concerns override the potential benefits of the drug.

Safety was the main concern for FDA especially with diet pills that has a history of health risks. For Qnexa, the FDA addressed extensively for five safety concerns including possible psychiatric problems like depression and suicidal thinking, impaired memory and concentration, acid buildup in bodily fluids that could increase the risk of kidney stones, an increase in heart rate and possible birth defects.

Final decision on whether to approve Qnexa is scheduled to be made by late October.

Two other weight-loss drugs submitted for FDA’s approval are Lorcaserin and Contrave. Orexigen’s Contrave is a combination of naltrexone (used to fight alcohol and drug addiction), and the antidepressant bupropion. Naltrexone’s side effects include gallbladder inflammation, seizure, palpitations, paresthesia and vertigo. Buproprion is may cause suicide. For Contrave, nausea is noted as a side effect.

Arena Pharmaceuticals’ locaserin is the first novel drug shown to have least health risks. Study reported little signs of side effects in patients other than headaches and dizziness that were no worse with the drug than placebo. Although more comprehensive study needs to done, the drug did not raise heart rates or blood pressure.

Lorcaserin is set for an FDA panel review in September and Contrave in December.