A number of cardiologists and nephrologists have begun questioning the safety and effectiveness of Abbott Laboratories’ best-selling drug TriCor. They are concerned the drug may cause decline in kidney functions, which could result in an increase in cardiac events.

TriCor, generic name fenofibrate, lowers non-cholesterol fat and is estimated to contribute 5 percent of Abbott’s total expected revenue for 2007.

Abbott executives and U.S. Food and Drug Administration (FDA) officials have said there is no reason for concern because there is no indication TriCor causes adverse kidney events.

However, concerns about TriCor focus on creatinine, a substance produced by muscles and eliminated by kidneys. A rise in creatinine can indicate kidney malfunction.

A study by Dr. Steven Nissen published in the March 2007 Journal of the American Medical Association found 38 percent of the patients who took TriCor saw creatinine levels rise above what is considered the upper limits of normal.

“There is concern raised by the finding but it is not definitive,” Nissen said, adding further tests need to be conducted to ensure TriCor is safe. Dr. Nissen recently made headlines when he raised safety concerns about GlaxoSmithKline’s diabetes drug Avandia. He also voiced concerns about Merck’s painkiller Vioxx.

TriCor has been prescribed to 2 million patients and has been approved for nearly 10 years in the United States.

Sources: “Drug concerns could hurt Abbott Labs stock: Report,” TherapeuticsDaily.com, June 4, 2007; Jacqueline Doherty, “Trials ahead for a drug maker,” SmartMoney.com, June 6, 2007.