Oct 28 (Reuters) - U.S. Food and Drug Administration staff reviewers recommended approval of a 60 mg dose of Daiichi Sankyo Co's blood thinner for certain atrial fibrillation patients, but suggested limiting its use in those with abnormal kidney function.

The drug, edoxaban, is a once-daily anticoagulant that inhibits Factor Xa, a protein playing a central role in blood-clotting.

Edoxaban is being considered for use in some patients with atrial fibrillation, characterized by a rapid and irregular heartbeat that can cause strokes.

"Although the ... overall findings support effectiveness, efficacy outcomes by baseline renal function have potential implications for approval or labeling," the reviewers said.

The report comes two days ahead of a meeting of independent experts to discuss the drug and recommend if it should be approved.

While the FDA is not obligated to follow the recommendations of its advisory panels, it typically does so.

Although edoxaban is as effective as the widely used anticoagulant warfarin, two other currently approved drugs in the same class are more effective than warfarin, the agency staff noted. (http://1.usa.gov/1wHOZW8)

"It's obvious to question whether edoxaban could be inferior to other approved therapies and whether this constitutes a reason not to approve," the reviewers said.

(Reporting by Natalie Grover in Bangalore; Editing by Simon Jennings)