Those "en vogue" drugs being developed for conditions like bipolar disease and diabetes may need a larger warning label. A team of researchers from Thomas Jefferson University claims the drugs may have adverse effects on the heart.

The drugs in question are inhibitors of GSK-3 proteins, which lead researcher Thomas Force says may cause serious heart defects in mice. In particular, mice lacking GSK-3-alpha were found to have enlarged heart muscle cells and hearts, which in turn, showed an inability to contract optimally.

Furthermore, in a model of high blood pressure, mice lacking GSK-3-alpha developed much more severe heart defects than did normal mice. These and other data lead the authors to conclude that in the absence of GSK-3-alpha, the mouse heart cannot respond effectively to high blood pressure and rapidly fails, raising concern that therapeutic GSK-3 inhibitors might have serious adverse effects.

Source: Thomas Jefferson University in Philadelphia, June 3, 2010