Just one week after an FDA advisory committee voted unanimously to recommend Bridion, the agency has extended the review period by three months, which means the anesthesia drug won’t be available until the fall, instead of next month, according to a filing with the Securities and Exchange Commission.

The med is supposed to be used for reversing the effects of certain muscle relaxants and helping patients recover more quickly from anesthesia after procedures. Despite the unanimous vote, the panel recommendation came with some caveats - post-marketing studies should address an allergic reaction marked at times by rash and flushing, and electrical disturbances in the heart. In explaining the delay, Schering-Plough says the FDA wants to review data on hypersensitivity.

Wall Street expected the only issue surrounding Bridion to be price - one analyst last speculated that Bridion could cost up to $100, compared to only a fraction for standard drugs now used to reverse the effects of muscle relaxants. Analysts forecast annual Bridion sales of about $400 million to $550 million, not enough to qualify as a blockbuster, but a significant contribution to badly needed sales. In an investor note this morning, Deutsche Bank analyst Barbara Ryan writes that she still expects the FDA to approve the drug.