WASHINGTON, April 24 (Xinhua) -- The U.S. Food and Drug Administration (FDA) has no effective process for responding quickly to emerging post-market drug safety problems, said a congressional study released Monday.

    The Government Accountability Office (GAO) meanwhile in the report called on Congress to grant FDA more authority to require drug companies conduct timely safety studies of on-market drugs that they promised before gaining the FDA approval but often delayed. FDA's ability to order such studies is limited, the report said.

    The agency can sometimes lack useful data in determining whether an approved drug really is safe, and it, at the same time, has no clear policies for addressing drug safety issues.

    "FDA lacks clear and effective processes for making decisions about and providing management oversight of, post-market safety issues," the report said.

    In a formal response included in the report, FDA said the "conclusions reached were reasonable and consistent with actions we already have underway or planned. "

    The GAO investigation was requested by Congress in 2004 after the sudden withdrawal of painkiller Vioxx, the long-term use of which were in studies linked to increased risk of heart attacks and strokes.

    The GAO report also noticed the dispute between the FDA's Office of Drug Safety and the larger Office of New Drugs, the two arms that now assess drug safety.

    As for FDA's Drug Safety Oversight Board, which was created following the Vioxx withdrawal, the GAO report said that, while it may help provide greater oversight of high-level safety decisions,"it does not address the lack of systematic tracking of ongoing safety issues." Enditem