Yasmin birth control pills are among those that contain drospirenone, a synthetic hormone that appears to carry an elevated risk for blood clots. Gnarls Monkey/Flickr hide caption

itoggle caption Gnarls Monkey/Flickr

Mixing antidepressant Paxil and the cholesterol-fighter Pravachol may lead to an unexpected increase in blood sugar, researchers say. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images