Canine version of Vioxx can be deadly

The drug came on the market four years ago after being tested in a healthy, young population, although it was intended for use by the old and sick. The manufacturer aggressively advertised it and ultimately made claims deemed by regulators to be beyond what testing had established.

When reports of illness and death linked to the drug surfaced not long after it went on the market, the company was slow to report the problems to the Food and Drug Administration (FDA). The agency eventually issued a reprimand and a formal warning letter, but two years later, the drug is still being sold, and some consumers complain that too little is being done to warn people of its dangers.

The medication is Deramaxx, and it's the center of another drug controversy. But this medication isn't for people. It's for dogs.

An anti-inflammatory closely related to the human painkiller Vioxx, which was taken off the market in 2004 and is the subject of thousands of lawsuits against its maker, Merck, Deramaxx has helped relieve many canine aches and pains.

But in an echo of the national debate over the dangerous side effects of some popular human drugs, Deramaxx has also proved at times to be deadly.

Before the early 1990s, most drugs given to pets were human medications that also seemed to help animals.

But with dogs, in particular, living longer and being treated increasingly as members of the family, the demand for better drugs has grown, along with the public's willingness to pay for them.

Most companies that develop and sell pet drugs are subsidiaries or divisions of the major brand-name drug companies, and they are required to seek FDA approval to market their products.

Deramaxx is not the only drug to run into trouble. The widely used ProHeart 6 heartworm treatment was the subject of controversy several years ago and was withdrawn in 2004 after reports that healthy dogs were becoming sick and dying after getting a shot of the preventive medicine.

In both cases, the deadly side effects led to formal — but by many accounts ineffective — government and industry efforts to warn veterinarians and dog owners of the drugs' risks.

In 1999, 300 pet owners sued Pfizer, alleging that its early dog-arthritis medicine Rimadyl had seriously harmed their animals. Pfizer settled in 2003, saying it had done nothing wrong but wanted to avoid costly litigation. Each plaintiff was given $1,000.

The ProHeart 6 case also led to allegations that its manufacturer, Wyeth, had sought to discredit the FDA official overseeing the investigation, a pattern seen with FDA officials who questioned the safety of human drugs.

Victoria Hampshire, the agency official at the center of the ProHeart 6 controversy, was taken off the case and later became a whistle-blower.

Her difficulties were described on the Senate floor last winter by Sen. Charles Grassley, R-Iowa.

Official cleared

Wyeth maintains that it simply gave the FDA potentially troubling information it found on a Web site about a possible conflict of interest involving Hampshire. The agency cleared her after an investigation, and ProHeart 6 remains off the market.

Hampshire said she became increasingly alarmed after receiving reports of hundreds of dogs dying soon after receiving the heartworm shots, just as more than 350 reports of deaths linked to Deramaxx have come into the FDA's Center for Veterinary Medicine.

As with adverse reactions in people, the number of reported cases is generally believed to represent less than 10 percent of the true total.

Hampshire, who now works in a different FDA division, said she learned about many cases from distraught pet owners such as Demitry Herman, a manager with Lehigh Electric in Allentown, Pa.

"This is really the same thing we saw with dangerous drugs being given to people, but maybe even more unfair because pet owners had no idea these pills could be so harmful," said Herman, who helped start a Web site dedicated to reporting on adverse drug reactions in dogs — www.dogsadversereactions.com — after his miniature schnauzer died after being given Deramaxx.

"If our vet had only told us what danger signs to look for, maybe we could have acted sooner and she wouldn't have had to die the miserable death she did," he said.

Adverse reactions

Herman's complaint is one David Stansfield, director of professional relations for Novartis Animal Health, the maker of Deramaxx, said he understands.

He said the company tells veterinarians to inform pet owners of possible side effects and to conduct blood and sometimes urine tests before the drug is prescribed. Those tests can be expensive, however, and are not routinely done.

Stephen Sundlof, director of the Center for Veterinary Medicine, said the agency thinks pet owners need better information about possible adverse reactions, but the agency cannot require veterinarians to give the consumer information drug companies provide, he said.

Stansfield said that when it comes to treating chronic and acute canine pain, the new medicines are a major step forward. His company has worked hard to improve its reporting of adverse events, he said, because it understands that the benefits come with risks.

FDA's Hampshire, said, "Whatever problems we face with drugs in the human world are magnified in the animal world. There's no pharmacist involved, and so there's no monitoring of prescriptions. And, of course, the patient can't talk and tell you he doesn't feel right."

Hampshire remains concerned about her agency's response to reports of serious side effects. She likens her experience to that of two other FDA whistle-blowers whose concerns about human drugs were not being properly addressed: safety officers David Graham (Vioxx) and Andrew Mosholder (antidepressants).

"Nobody wanted to believe I was just doing my job; they wanted to think I was off on my own agenda," said Hampshire, who last month won the U.S. Public Health Service's award for veterinarian of the year. "I think a lot of people [in the agency] didn't want to hear what I was saying."