Midodrine- withdrawal and approval

The US FDA did a U-turn on its 2-week old decision of withdrawing Midodrine from the market. On August 16, 2010 the U.S. FDA proposed to withdraw approval of the drug Midodrine hydrochloride, used to treat the low blood pressure condition orthostatic hypotension, because required post-approval studies that verify the clinical benefit of the drug have not been done.
It was also mentioned that the patients who currently take this medication should not stop taking it and should consult their health care professional about other treatment options.
The drug, marketed as ProAmatine by Shire Development Inc. and as a generic by others, was approved in 1996 under the FDA’s accelerated approval regulations for drugs that treat serious or life-threatening diseases. That approval required that the manufacturer verify clinical benefit to patients through post-approval studies.
According to the information, till date, neither the original manufacturer nor any generic manufacturer had demonstrated the drug’s clinical benefit, for example, by showing that use of the drug improved a patient’s ability to perform life activities. Orthostatic hypotension is a condition in which patients are unable to maintain blood pressure in the upright position and, therefore, become dizzy or faint when they stand up.
In the same information it was clarified that drug companies that obtain approval under this program are required to conduct additional clinical trials after approval to confirm the drug’s benefit. If those trials fail to confirm clinical benefit to patients, or if the companies do not pursue the required confirmatory trials with due diligence, the FDA can withdraw approval of the drug using expedited procedures.
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm222580.htm
The second announcement came after two weeks that the US FDA will make sure that midodrine continues to be available to the 100 000 patients who use the drug while it tries to resolve the issue that originally prompted the planned withdrawal: further post marketing studies . After the withdrawal, extensive lobbying by the physicians and the patients led to a re-think by FDA and earlier announcement was withdrawn.
Although Shire Pharmaceuticals (which holds the new drug application for midodrine under the brand name ProAmatine), did conduct some post marketing trials, the FDA said these were inconclusive and required that additional studies be conducted for the product to maintain its marketing authorization.
http://www.theheart.org/article/1119697.do