The blockbuster cholesterol drug Vytorin failed to improve a rare heart valve condition called aortic stenosis and seemed to increase rates of cancer, a new study says, dealing another blow to the top-selling drug and its makers, Merck and Schering-Plough .

FORBES: Another Blow For Merck And Schering

For certain heart conditions, antibiotics are recommended about one hour before invasive medical procedures to prevent a condition called infective endocarditis, which is a potentially life-threatening bacterial infection of the inner lining or valve within the heart.

CNN: Why do I no longer need an antibiotic before teeth cleaning?