A post-market analysis of cholesterol-lowering drugs called statins indicates that some of the most serious side effects may be higher in one of the newest drugs, Crestor (rosuvastatin). Researchers found that rosuvastatin was associated with a higher rate of muscle and kidney complications than the older statins. The drug is the strongest statin available because it has the greatest effect per milligram on low-density lipoprotein (bad cholesterol), according to the report in Journal of the American Heart Association.

However, researchers emphasize that the risk involved in taking this drug is low, and that statins are still the best drugs for treating elevated cholesterol and reducing a person's risk for developing heart disease and stroke. If a patient has side effects, they generally go away when the patient stops taking the drug.

As reported in Circulation: Journal of the American Heart Association, the researchers analyzed adverse events reports (AERS) sent to the US Food and Drug Administration for rosuvastatin and compared them to AERS rates during the same concurrent time period for three other statins: atorvastatin (Lipitor), simvastatin (Zocor) and pravastatin (Pravachol).

The researchers also compared AERS rates during the first year of marketing of each of the statins, which allowed a comparison of rosuvastatin to the three statins as well as to cerivastatin (Baycol). Cerivastatin, the most potent statin per milligram ever to receive FDA approval, was withdrawn from the market in 2001 after the FDA received numerous reports of severe myopathy (muscle weakness), rhabdomyolysis (muscle deterioration resulting in toxins released in the blood that can lead to renal failure), proteinuria (protein in the urine), nephropathy (a reduced ability of the kidneys to filter toxins from the blood) and kidney failure.

"The absolute risk with this statin is low. The overwhelming majority of people who are taking it will have no problem at all," Alice K. Jacobs, president of the American Heart Association said adding, "This analysis shows that statins are safe, and that physicians should continue to offer their patients what is still one of the best tools we have for treating elevated cholesterol."

In the primary analysis, researchers looked for side effects that included four muscle or kidney complications: rhabdomyolysis (muscle deterioration resulting in toxins released in the blood that can lead to renal failure), proteinuria (protein in the urine), nephropathy (a reduced ability of the kidneys to filter toxins from the blood) and kidney failure. When the AERS was compared to the four drugs over the same concurrent time period, the rate of rosuvastatin AERS was significantly higher than the other statins. The same findings were true when the four statins were compared at the one-year marketing time period, with the exception that both rosuvastatin and simvastatin had higher AERS than pravastatin or atorvastatin.

Researchers found that the risk of the AERS occurred relatively earlier after the start of rosuvastatin therapy, usually within the first 12 weeks. In addition, 62 per cent of the AERS occurred at the 10-milligram (mg) dose or less. Fatalities occurred in only a few cases, with death rates in patients taking rosuvastatin and simvastatin being lower than the other statins (pravastatin and atorvastatin).

Richard H. Karas, director of the Preventive Cardiology Centre, said post-marketing analyses like this one can help identify safety concerns that might be missed by pre-marketing trials that typically exclude patients who may be at greater risk of certain side effects but who are likely to receive a drug after it's marketed. Pre-marketing trials that assess safety or efficacy also often don't detect relatively rare adverse events.

Meanwhile, rejecting a citizen's petition to remove Crestor from the market, the US FDA has opined Crestor, which has been aggressively marketed by AstraZeneca LP, appeared to be no more dangerous than other statins for most people.