This vote was on an amendment offered by Chuck Grassley, R-Iowa, that would require that drug safety actions taken by the Food and Drug Administration be reviewed and approved by the agency's Office of Surveillance and Epidemiology. This office is responsible for monitoring newly-approved drugs for adverse reactions after they have been approved for sale. Currently, the Office of Surveillance serves as an advisor to the Office of New Drugs (which decides whether or not to approve a drug for sale in the United States), but has little enforcement authority. Grassley's amendment would require that the two offices share decision-making authority.

The amendment was offered to a bill that would overhaul the FDA's drug approval program. This program essentially allows pharmaceutical companies to pay the FDA to review and possibly approve their new drugs, if they are found to be safe.

Grassley, a long-time critic of the FDA who believes the agency is too beholden to the pharmaceutical industry, said the Office of Surveillance does not have the authority to take action if a drug is found to be unsafe once it's approved. For instance, Grassley said the Office of Surveillance warned the Office of New Drugs about several recently-approved drugs that ended up displaying serious long-term health effects (such as Avandia, which has been linked with increased risk of heart attacks). However, those warnings were never incorporated into drug labeling or communications to pharmaceutical manufacturers.

"We have to have it so that we have enough independent decisionmaking within the FDA to make sure these drugs are safe," Grassley said. "This amendment provides an approach with checks and balances between the office that approves a drug for marketing and the office that watches a drug once it is on the market."

Mike Enzi, R-Wyo. and one of the bill's sponsors, opposed Grassley's amendment, saying it would add an "unnecessary layer of bureaucracy into an agency that we have designed to be nimble and responsive in their process to deal with emerging drug safety issues."

Enzi said the underlying bill establishes a dispute resolution process, and that it contains all the necessary tools to address the concerns Grassley raised.

The amendment was rejected on a vote of 46-47, with a handful of members from both parties peeling off. Republicans mostly voted against the amendment, though five did not. And Democrats mostly voted for the amendment, though eight did not. The most progressive members of the Senate voted for the amendment, excepting Ted Kennedy, D-Mass., who voted no (Kennedy is one of the main sponsors of the underlying bill, along with Enzi).