The FDA approves BioCryst Pharmaceuticals' (NASDAQ:BCRX) Rapivab (peramir injection) for the treatment of adult (18 years and older) patients with acute uncomplicated influenza who have been symptomatic for no more than two days. Rapivab is a neuraminidase inhibitor that is administered as a single 600 mg dose intravenously over 15 to 30 minutes.