The US Food and Drug Administration (FDA) may withdraw approval of midodrine hydrochloride, a drug used to treat patients who develop low blood pressure when upright, because the drug's manufacturers did not fulfill requirements for postmarket studies.
The drug was approved in 1996 through the agency's accelerated approval program on the basis of clinical trials that demonstrated it improved blood pressure, a surrogate end point. At that time, the agency required postmarket studies to verify the clinical benefit of the drug, such as whether it improved patient's ability to participate in day-to-day activities. According to the FDA, those requirements have not been met, so the agency sent letters to the manufacturers of the drugs proposing a withdrawal. Shire, the manufacturer of the brand-name version, ProAmatine, said in a press release that it had already planned to remove the drug in September.