Pfizer's Spiriva may raise risk of stroke-US FDA

WASHINGTON, March 18 (Reuters) - Use of Pfizer Inc (PFE.N) and Boehringer Ingelheim Pharmaceutical Inc's lung drug Spiriva may increase the risk of stroke, the U.S. Food and Drug Administration said on Tuesday.

The FDA said the risk was not yet conclusive and was part of the agency's effort to tell doctors and patients about potential problems as soon as possible.

Spiriva HandiHaler is used to treat chronic obstructive pulmonary disease, or COPD, and is co-promoted worldwide by Pfizer and Germany's Boehringer Ingelheim. (Reporting by Susan Heavey; Editing by Steve Orlofsky)