Cholesterol Drug Crestor Poses Risks, Journal Says
Tuesday, May 24, 2005
The powerful cholesterol-lowering drug Crestor is significantly more likely than other statins to cause muscle deterioration that can lead to kidney disease and failure, according to a study in the American Heart Association's journal, Circulation.
The conclusion is at odds with the most recent recommendation of the Food and Drug Administration, which in March rejected a citizen's petition to remove Crestor from the market. At the time, the FDA said Crestor, which has been aggressively marketed by AstraZeneca LP, appeared to be no more dangerous than other statins for most people.
Based on the number of side effects reported to the FDA, however, the researchers said yesterday that Crestor was two to six times as likely to cause complications over a one-year period as three other statins on the market.
Although the number of serious side effects reported by Crestor users was small, the study authors said the higher rate convinced them that doctors should try their patients on other statins and only turn to Crestor as a last resort.
The study "raises concerns about the safety of this drug at the range of doses used in common clinical practice," the study concludes. "It would seem prudent at the current time for health care providers to consider other statins as first-line therapy."
AstraZeneca defended its billion-dollar-a-year drug, saying "we strongly disagree with the conclusions of this study." In a statement, the company said the FDA's voluntary system for soliciting reports of complications, called "adverse events," does not confirm the accuracy of the accounts it gets and so cannot be used to determine a drug's risks.
The company cited the FDA's recent conclusion that based on all the evidence available, Crestor does not pose an unacceptable risk. "AstraZeneca again reaffirms that the safety profile of Crestor is in line with other marketed statins, and is a highly effective cholesterol-lowering therapy," it said.
With drug safety an increasingly hot topic with the public, doctors and members of Congress, the Circulation paper quickly became a new source of controversy.
Sidney M. Wolfe of Public Citizen Health Research Group, who filed the petition rejected by the FDA, said the study confirmed his conclusions.
"This should be very embarrassing to the FDA," Wolfe said. He said that unlike the arthritis painkillers Vioxx and Bextra, which were recently taken off the market because of harmful side effects, Crestor's potential to cause muscle and kidney damage was known before the drug was approved.
"Short of having the drug taken off the market, I don't think that anything could contribute to the end of a drug more than this paper," Wolfe said.
Scott M. Grundy, a University of Texas Southwestern Medical Center researcher long associated with efforts to reduce cholesterol levels to prevent heart disease, defended the drug. Grundy, in a commentary accompanying the research paper, said he was not convinced that the risks from the higher potency of Crestor outweighed its possible benefits to patients with especially high cholesterol levels.
The American Heart Association -- which did not take a position on either the study or the accompanying commentary -- held a teleconference yesterday to discuss the study and its view that patients should continue on whatever statins their doctors prescribe. Grundy said he would prescribe Crestor now as readily as any other statin. But Richard H. Karas of Tufts-New England Medical Center, lead author of the Circulation paper, said he would recommend Crestor only as a last resort.
Both Karas and Grundy have received research contracts and speaking fees from statin makers, including AstraZeneca. The heart association also receives considerable financial support from drug companies.
Crestor, which was approved by the FDA in 2003, is agreed to be the most potent statin on the market. Its higher strength, however, does not make a dramatic difference in studies. While statins such as Lipitor, Zocor and Pravachol lower LDL -- or harmful -- cholesterol by 50 to 55 percent, Crestor decreases it by 55 to 60 percent, said Grundy and Karas.
In the new study, doctors of patients taking Crestor were significantly more likely to report complications of kidney disease and rhabdomylosis, a muscle deterioration that releases toxins into the blood that can cause renal failure. The overall number was small -- 145 muscle or kidney problems out of 5.2 million prescriptions during the drug's first year on the market -- but the number was substantially higher than for other statins.
In 2001, the FDA took Baycol, a considerably more powerful statin than Crestor, off the market because of similar side effects. In a congressional hearing last December, FDA drug safety officer and whistle-blower David Graham identified Crestor as one of five drugs now on the market that he believed posed serious safety problems that were not balanced by their benefits.
The FDA yesterday referred callers to its March conclusions that Crestor is no more hazardous than other statins.