Merck deserves some sympathy, but not a lot, for the staggering loss it suffered last week in a case involving its painkiller Vioxx, which was withdrawn from the market because it raises the risk of heart attacks and strokes in a small percentage of patients. A Texas jury hit Merck with a symbolically staggering $253.5 million judgment (it will be reduced to $26.1 million under a Texas law capping punitive damages) even though the evidence that Vioxx actually caused the victim's death was extremely thin. The verdict may reflect the fact that Merck was facing an extremely capable lawyer, while its own lawyers committed blunders that alienated the jury. But before heaping too much sympathy on the beleaguered drugmaker, it is important to note that Merck brought a lot of this problem on itself - by failing to react quickly to evidence that Vioxx can be harmful in some patients and by promoting the drug beyond any rational use.

Vioxx is in a class of painkillers known as cox-2 inhibitors. These drugs are, in general, no more effective than many older nonprescription drugs at relieving pain. Their presumed advantage is that they reduce the risk of the gastrointestinal bleeding and ulcers that afflict a minority of patients who take the older painkillers. Unfortunately, aggressive marketing propelled them to wide use by people at little risk of gastrointestinal side effects. Vioxx itself was used by more than 20 million people before it was withdrawn last September because a clinical study found cardiovascular problems in some patients who used it for longer than 18 months.

Merck is now facing more than 4,000 lawsuits, and analysts estimate that it may ultimately have to pay tens of billions of dollars in liability awards to plaintiffs drawn from the huge pool of Vioxx users. That pool is much larger than it should have been because of the overmarketing of Vioxx.

The Texas case - the first to go to trial - was filed by the widow of a man who died of an arrhythmia, or irregular heartbeat, after taking Vioxx. There is a good possibility that Vioxx was not responsible for his death. A coroner had listed the cause of death as arrhythmia and Vioxx has never been linked to arrhythmias, so many experts considered the case against Merck quite weak. Even so, the jury bought the speculative theory put forth by the plaintiff's lawyer that the arrhythmia had been caused by a heart attack that acted so quickly it left no muscle damage visible at autopsy. The heart attack was presumed to have been caused by an undetected blood clot that, in turn, was blamed on Vioxx. The key evidence supporting this theory was a statement by the coroner that she believed a blood clot killed the victim, even though she had not mentioned that possibility in her autopsy report.

That is an extremely flimsy scientific basis for holding Vioxx responsible, but this case was less about science than about punishing Merck for what jurors considered an egregious history of covering up evidence of risk while promoting the drug so heavily to consumers. Internal e-mail messages and documents showed that Merck scientists had been concerned about cardiovascular risks even before Vioxx went on the market and continued to be concerned thereafter, even while resisting regulatory efforts to add warnings to the drug's label and devising strategies to dodge any concerns from doctors.

Merck loyalists contend that the e-mail notes were taken out of context and that the company made responsible decisions based on the fragmentary signals of risk it had in hand. But surely the overriding message sent by this verdict is that companies must jump at the first hint of risk and warn patients and doctors of any dangers as clearly and quickly as possible. They should not be stonewalling regulators, soft-pedaling risk to doctors or promoting drugs to millions of people who don't need them.