The safety of AstraZeneca’s cholesterol-lowering drug, Crestor (rosuvastatin), has come under the spotlight once again after new research suggested that it caused more serious side effects than competing products.

Back in March, the US Food and Drug Administration rejected a petition from influential consumer group, Public Citizen, which aimed to remove the drug from the market, saying that available evidence indicated that Crestor did not pose a risk of muscle toxicity greater than the other approved statins, and that there was no convincing evidence that Crestor poses a serious risk of renal injury [[15/03/05b]]. However, the latest study, which was published in the American Heart Association’s journal, Circulation, reviewed a national side effect database and found that Crestor’s safety profile was worse than the three most commonly used statins – Pfizer’s Lipitor (atorvastatin), Bristol-Myers Squibb’s Pravachol (pravastatin), Merck & Co’s Zocor (simvastatin). The most serious side effects were kidney damage and muscle weakness, which frequently resulted in patients requiring hospitalisation. The study also pitted Crestor against Bayer’s Baycol/Lipobay (cerivastatin), which was pulled from the market in 2001 after a number of patients died whilst taking the drug [[08/08/01a]], but found that AstraZeneca’s offering had less than half the rate of the side effects reported for Lipobay during its first year.

Nevertheless, study author, Richard Karas of Tufts New England Medical Centre, said that it was important to note that, as a family, statins are “very safe drugs that have clearly been shown to reduce the risk of heart disease.” He added: “Although Crestor was found to be less safe than others, it does not mean patients should immediately stop taking this medication. In fact, the overall risks of [Crestor] remain low, and people taking this drug should talk to their doctor before deciding whether to continue on it or stop it.” He went on to say that the study raised concerns about the drug’s safety at the range of doses currently used, and recommended doctors consider other statins as first-line therapy.

Perhaps unsurprisingly, the Anglo-Swedish drug firm has come out fighting, saying that the data are “misleading” and create “unnecessary alarm.” The company adds that the data stand in direct contrast to an FDA document issued when the agency rejected Public Citizen’s calls to pull the drug. Furthermore, AstraZeneca notes that the FDA’s own disclaimer states that the adverse event reporting system “has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of adverse drug reactions.”