Drugs, water retention tied to heart risks

CLEVELAND, Feb. 26 (UPI) -- Fluid retention may explain why medications such as Vioxx, Bextra and Avandia can increase the risk of heart attacks and strokes, U.S. researchers suggest.

Dr. Robert P. Blankfield of Case Western Reserve University School of Medicine in Cleveland used several basic cardiovascular and hydraulic equations to demonstrate that fluid retention is detrimental for the cardiovascular system.

Fluid retention increases the likelihood that blood will flow in a turbulent manner, which in turn accelerates hardening of the arteries and increasing the risk of heart attacks and strokes, Blankfield says.

Many medications cause fluid retention and while they raise blood pressure in some, they do not increase blood pressure in others. Physicians worry about fluid retention if it does raise blood pressure, but are unconcerned when blood pressure is unaffected, the study says.

"This paper demonstrates that fluid retention is unhealthy because it increases the likelihood that blood will flow in a turbulent manner regardless of whether or not blood pressure is raised," Blankfield says in a statement.

"If the Food and Drug Administration had been aware of the increased cardiovascular risk that arises from drugs that cause fluid retention, Vioxx, Bextra and Avandia might never have been approved."

The pain medications Vioxx and Bextra and the anti-diabetic medication Avandia cause fluid retention. Vioxx and Bextra, were withdrawn from the market because of concerns of heart attacks and strokes, while Avandia has been suspected in some reports of increasing the risk of heart attacks, Blankfield says.