VIVUS, Inc. (NASDAQ:VVUS), the maker of much-needed obesity drugs in the United States, announced that newly installed Chief Executive Officer Tony Zook has left the company today due to lingering health reasons. Zook’s reign as CEO lasted just over a month following the company overturning its board and management following a proxy fight with its largest shareholder this summer.

Vivus

Vivus to hire Seth H.Z. Fischer as Zook CEO

Seth H.Z. Fischer, a former employee of Johnson & Johnson (NYSE:JNJ), will step into Zook’s role as Chief Executive Officer immediately following his departure to deal with “recurring issues associated with a previously diagnosed medical condition,” according to VIVUS, Inc. (NASDAQ:VVUS) in a statement today.

First Manhattan Co. and Sarissa Capital Management LP ousted former chief Leland Wilson when they won control of the board in July. Zook was given the title of CEO on July 22nd following this ugly fight. Given the limited time that Zook led Vivus Inc., his job will remain largely the same: finding a marketing partner for the obesity drug Qsymia, while looking to expand its use. Europe remains an important market for Qsymia, but in order to reach it, VIVUS, Inc. (NASDAQ:VVUS) will have to work hard to reduce costs at the same time.

“This has been a difficult decision,” Zook said in the statement. “Unfortunately, I cannot devote the necessary time and focus to the company, but instead must concentrate on personal health issues.”

VIVUS shares fall

VIVUS, Inc. (NASDAQ:VVUS) shares dropped immediately following the announcement. At 9:32 a.m. New York time, shares had dropped 1.3 percent. This, however, was short lived with the stock rebounding and finishing up nearly 3 (2.95) percent at $12.90. Single day gains like this have not been forthcoming for Vivus; the stock has lost over 42% of its value in the 12 months ending August 30.

The primary reason for the drop has been lower-than-expected sales of Qsymia, which was approved in July 2012. For the last quarter, sales were largely flat at $5.5 million with analysts’ estimates ranging from $7-8 million for the quarter.

Fischer left Johnson & Johnson (NYSE:JNJ) last year after working as company group chairman and worldwide franchise chairman of Cordis Corp. Prior to taking that position, he was J&J’s company group chairman of North America Pharmaceuticals. He helped oversee the selling of medicines including Topamax, a treatment for migraines and epilepsy whose ingredient topiramate is also part of Qsymia.

Get better Mr. Zook, and know that VIVUS, Inc. (NASDAQ:VVUS) should be in good hands.