INDIANAPOLIS (AP) — Eli Lilly and Co. said Wednesday the blood thinner Effient has finally reached U.S. pharmacy shelves. The Indianapolis company said Effient is now available across the United States. The Food and Drug Administration approved it on July 10 after delaying its decision several times during an 18-month review. European regulators approved the drug in February. The FDA has said the drug will carry a boxed warning to alert physicians to the risks of “significant, sometimes fatal, bleeding” in some patients. Effient prevents platelets from sticking together and forming potentially dangerous clots. It is approved for patients undergoing angioplasty, a procedure in which an inflatable balloon is used to clear arteries clogged with plaque, which are often propped open with a stent. Effient will compete with Plavix, the world’s second-best selling medication, made by Sanofi-Aventis and Bristol-Myers Squibb. Some analysts have said Effient could eventually exceed $1 billion in annual sales. That would provide a crucial revenue source for Lilly, which faces patent expirations for several top-selling drugs starting in 2011. But Lilly will share Effient revenue with Japanese drugmaker and Effient co-developer Daiichi Sankyo Co.