BETHESDA, Md. -- Federal officials said Friday they have linked 38 cases of acute liver failure to the diabetes drug Rezulin and believe the risk of liver problems grows over time as patients take the drug.
In all, Food and Drug Administration officials have discovered 43 cases of acute liver failure among Rezulin patients, 38 of which were probably caused by the medicine, the officials told a panel of scientific advisers weighing the drug's safety.Of those 43 people, seven had a liver transplant and survived, five survived without a transplant and 28 died. Officials did not know the outcome of the other three cases.
At the same time, several doctors told the FDA scientific advisers that Rezulin helps many of their toughest diabetes patients, and the benefits outweigh the risk.
"No drug is 100 percent safe," said Dr. Steven Edelman of the Veterans Affairs Medical Center in San Diego. "But diabetes is a serious disease."
Only an estimated 45 percent of Rezulin patients are getting the proper liver testing to detect problems in time to treat them, under the best-case scenario, said Dr. David Graham, an FDA epidemiologist. Thus, it's impossible to say if a better job of liver testing would save a significant number.
Very few Rezulin patients have used the drug for more than several months, but Graham argued that the longer patients do use it, the greater the risk of liver damage. Using the data that exist, Graham created a model to estimate that among people who use Rezulin for six months, as many as one in 1,800 could have liver failure.
The FDA believes it has received reports of only about 10 percent of the liver damage that may have occurred among Rezulin users, because there is no law requiring doctors to report patient side effects.
"There is no question that individual patients have benefited" from Rezulin, Graham said. But "the longer you stay on troglitazone (Rezulin), the greater the risk of developing acute liver failure."
The 16-month debate over the safety of the novel drug, taken by 750,000 Americans, has sharply divided diabetes specialists.
Of all the medications sold for type 2 or so-called adult onset diabetes, Rezulin is the only one that targets the disease's underlying cause. It has helped patients for whom other therapies failed and thus are at higher risk of serious complications.
But other specialists have stopped prescribing Rezulin because it can attack some patients' livers. On Monday, Britain ruled that Rezulin was too dangerous to sell in that country.