In the 1990s, after decades of taking a slow, skeptical approach to approving new medicines, the Food and Drug Administration responded to pressures from patient advocacy groups, private industry and Congress by streamlining the way it did its job.
Instead of acting as a suspicious cop, the FDA began to embrace a philosophy of working with the pharmaceutical industry as a trusted partner.
It is that sea change, critics say, that has led to the controversy over Vioxx and to charges that in recent years the agency has too often allowed unsafe drugs to reach the market -- with sometimes catastrophic results.
Even critics concede that the FDA's task is daunting: If it moves too slowly, as AIDS activists and others charged it did in an earlier era, patients may suffer or die. Move too quickly, and patients may be exposed to unrecognized risks.
"I think they're trying to do the right thing. They want to make sure that the public receives drugs that are as safe and effective as possible," said Steven W. Chen, an assistant professor at the USC School of Pharmacy.
Yet Chen also worried that the FDA had not reacted quickly enough to warning signs about Vioxx and other drugs.
"If they start seeing that there may be some increased risk, the FDA needs to be responsible," he said.
At about the same time the FDA was speeding up approvals for AIDS drugs, it also underwent a far-reaching change in its traditional financing. In 1992, Congress gave the agency authority to charge user fees for the cost of faster drug reviews.
Those fees were put in place to defray costs as part of a Republican agenda that emphasized private financing for certain government activities that helped private industry. User fees now cover more than half the nearly $500-million annual budget of the FDA's Center for Drug Evaluation and Research.
To critics, such fees represent a troubling corporate incursion into what should be an exclusively public realm, judging whether new drugs are ready for the marketplace.
"When you have a situation where the industry you are regulating is paying the bills for your regulatory activities, it changes the sense of who you're accountable to, and who's paying your salary," said Jerome Avorn, professor of medicine at Harvard Medical School and author of "Powerful Medicines: The Benefits, Risks and Costs of Prescription Drugs."
The FDA's journey from aloof regulator to partner of industry took a major step in the early 1990s, as concerns about AIDS crystallized broader public frustrations about slow approvals for desperately sought drugs.
AIDS activists demanding faster drug approval even protested at the FDA's headquarters in Rockville, Md. The push hit a strong political chord, and the FDA sped up its approvals for AIDS drugs.
"It really was the edge of the wedge" in getting the FDA to move faster, Avorn said.
AIDS patients were not the only Americans who yearned for faster help, however. Accounts of Americans traveling to foreign countries for medication became folklore.
Those stories intensified pressure on the FDA to streamline its tradition-bound bureaucracy.
The agency responded by creating a fast-track system for assessing so-called breakthrough drugs, stripping months off the traditional process for approval. AIDS drugs were among the first beneficiaries of the new system.
Some critics view the swifter approval of AIDS drugs as a precedent seized on by private industry to achieve a profit-oriented agenda of getting drugs into the marketplace with fewer hurdles.
"The drug companies saw this wonderful opportunity to piggyback on the AIDS activists' demand for faster approval process -- and FDA threw in everything," said Vera Hassner Sharav, president of the Alliance for Human Research Protection, a patient advocacy group in New York.
Others maintain that such complaints are off the mark, and that the FDA was responding to a legitimate public demand for the benefits of pharmaceutical innovations for other illnesses.
As some see it, marketing and economic trends have reinforced the FDA's new approach.
In the mid-1990s, for example, Americans provided one-third of the industry's global revenue, said Alan Sager, a professor of public health at Boston University. Today, this country accounts for half of the revenue.
That is partly explained by the fact that Americans pay higher prices for many drugs than do residents of other countries, and also by greater consumption.
Given such realities, pharmaceutical companies place intense pressure on the FDA and politicians to allow products into the lucrative U.S. marketplace.
The Bush administration has been accused of extending the new system even further, especially in the enforcement area. It has reduced the number of warning letters sent to companies after inspections, for example, and reduced the rate of drugs removed from the marketplace.
But FDA officials say they remain vigilant in protecting the public. In a statement this week, acting FDA Commissioner Lester M. Crawford tried to answer charges that his agency had been slow to respond to evidence that Vioxx and other drugs posed dangers.
The FDA, he said, would continue to decide whether to make drugs available only after vigorous debate on the scientific merits.
"It is a daunting task, and it is one that the FDA has been -- and continues to be -- committed to carrying out every day," he said.
Times staff writer Ricardo Alonso-Zaldivar contributed to this report.