'The FDA should not be slowing things down or speeding them up depending on how the wind blows,' said Sen. Charles E. Grassley, an Iowa Republican.

This new caution comes in the wake of sharp criticism from some members of Congress and consumer advocates who said the agency was doing a poor job of protecting the public from risks posed by drugs.

Vague Warnings, Confusing Advice

Much of the criticism followed the revelation last year that certain powerful painkillers called cox-2 inhibitors could increase heart attack and stroke risks.

The popular medicines Vioxx and Bextra were subsequently pulled from the market, and another, Celebrex, now carries a warning that it should be prescribed at the lowest effective dose for the shortest possible time.

The FDA's new conservative approach has failed to appease federal lawmakers and upset some doctors, who say the agency's vague warnings and confusing advice mean that physicians aren't getting the information they need to avoid health problems but will get blamed for them anyway.

And drug makers contend the new wave of warnings is scaring patients who could benefit from needed medicines, the Times said.

'How the Wind Blows'

"The FDA should not be slowing things down or speeding them up depending on how the wind blows," said Sen. Charles E. Grassley, an Iowa Republican. "Instead, the agency should be a rock of stability."

Traditionally, the FDA issued warnings about drugs only if studies demonstrated a clear risk. Now, the agency is issuing public alerts even when problems are only suspected, the newspaper said.

The FDA said it has not changed the way it regulates drugs.

"Maybe we're not being overly cautious but instead trying to be responsive," Dr. Scott Gottlieb, the agency's deputy commissioner, told the Times.