One of the components of Vivus Inc.'s obesity drug candidate Qnexa has come under the scanner of the US Food and Drug Administration for associated side effects. Following the development, the shares of Vivus Inc. fell over 3% to trade at $8.41 this morning.

Earlier, the Food and Drug Administration turned down approval to the drug in October. The side effects associated with Qnexa included significant weight loss, potential heart problems, suicidal thoughts, birth defects, and memory lapses in some patients.

With volume increasing from daily average of 2.12 million to 10.39 million, the small cap stock ended the day 16.20% lower at $8.74. Notably, Vivus Inc. shares have a 52-week range of $4.69-$13.68, as in the last 12 months the stock fell 4.48%.

The Food and Drug Administration has not ordered any fresh clinical trials, which could take a long time and lead to considerable new expenses for the Company. Even if the fresh trials were conducted, there were fears about Qnexa's chances of winning marketing approval.

Having pleaded its case before the Food and Drug Administration authorities on Wednesday, Vivus, a California-based biopharmaceutical Company, said the former asked it to "find out if it is feasible to analyze existing health care databases to determine how often women who use the drug topiramate as a migraine drug give birth to children who have cleft palates".