NEW YORK (AP) — Generic drugmaker Ranbaxy Laboratories Ltd. said Tuesday its U.S. subsidiary received final Food and Drug Administration approval on two generic doses of the migraine drug Imitrex. The India-based company said it will start shipping the 25-milligram and 50-milligram doses of the drug immediately. U.K.-based GlaxoSmithKline PLC makes the drug, which also carries the generic name sumatriptan. Ranbaxy said sales of the 25-milligram and 50-milligram doses of the drug reached $379 million over the year ended June 30, citing market researcher IMS Health Inc. On Monday, Canonsburg, Pa.-based generic drug developer Mylan Inc. said it started shipping generic versions of the drug.