Twenty-nine patients who took AstraZeneca Plc's (AZN) anti-cholesterol drug Crestor (search) have developed kidney damage, a U.S. consumer group said on Friday as it called again for a ban on the medicine.

The rate of reported kidney problems is about 75 times higher with Crestor than with all other drugs in the same class combined, consumer group Public Citizen (search) said. According to its analysis, there have been 6.4 reports of acute kidney failure or kidney damage for every 1 million Crestor prescriptions filled.

"It becomes clearer by the day that this drug is uniquely toxic without offering any unique benefit, and that it must be removed from the market," Dr. Sidney Wolfe, head of Public Citizen's Health Research Group, wrote in a letter to the Food and Drug Administration (search).

AstraZeneca insists Crestor, known generically as rosuvastatin, is as safe as other drugs in the family known as statins. The FDA has agreed but promised to closely monitor reports of safety problems.

"Our data shows, with regard to that particular adverse event, (Crestor) remains in line with other statins," company spokeswoman Emily Denney said.

AstraZeneca updates information about health problems reported in Crestor patients every week on its Web site www.rosuvastatininformation.com, Denney said. The "adverse event" reports often are incomplete and do not prove if a drug caused a particular problem, but the FDA uses them to look for signals of possible drug-induced hazards.

According to the site, "serious" kidney problems are "very rare" and occur at a rate of less than one in 10,000.

The company's main Web site, www.astrazeneca.com, has a link to www.rosuvastatininformation.com, but the AstraZeneca-run site for the drug -- http://www.crestor.com -- does not, Denney said.

Because of "some of the guidelines ... that the FDA institutes, we need to make sure we separate scientific information and promotional information," she said.

Public Citizen said its latest analysis was based on reports to the FDA since Crestor's approval in September 2003 through Aug. 26, 2004.

Millions of people worldwide take statins, such as Pfizer Inc.'s (PFE) Lipitor and Merck & Co Inc.'s (MRK) Zocor, to lower their cholesterol. High cholesterol is a major risk factor for heart disease.

Bayer AG's (search) statin Baycol (search) was pulled from the market in 2001 after it was linked to more than 100 deaths, many of them from a severe muscle-damaging condition called rhabdomyolysis.

The FDA has received 65 reports of rhabdomyolysis in Crestor patients, which is similar to the rate associated with Baycol, Public Citizen said. AstraZeneca says the problem, also linked to other statins, is rare with Crestor.