Researchers at the Lady Davis Institute for Medical Research in Quebec found that people who took high doses of simvastatin (Zocor), atorvastatin (Lipitor) or rosuvastatin (Crestor) had significantly increased risk of being admitted to the hospital with a serious condition called Acute Kidney Injury by 34 percent.

This class of drugs reduce levels of "bad" cholesterol in the blood and attempt to reduce the risk of heart disease, heart attack and stroke. Doctors prescribe different dosages depending on the levels of cholesterol that blood tests reveal. Researchers at the Lady Davis Institute for Medical Research in Quebec defined high doses as 40mg+ for simvastatin, 20mg+ for atorvastatin, and 10mg+ for rosuvastatin.

Researchers examined the medical records of two million Canadians and saw that the risk of acute kidney injury was increased by 34 percent compared to people who were on lower doses of the medications. They examined the first 120 days of treatment, but said that the risk carried on for two years.

Dr. Robert G. Fassett and Jeff S. Coombes, both professors, concluded in an accompanying editorial: "Despite extensive experience with the use of statins over many years, optimization of doses to derive benefit but minimise risk is still evolving. The results of the current study indicate that a randomised controlled trial is needed to compare the adverse effects of high and low potency statins. However, because rare adverse events are not always seen in trials, postmarketing surveillance and reporting from large databases will still be needed to quantify these."

The report published in the British Medical Journal can be found here.