 The purpose of this study is to find out if a drug interaction occurs when glyburide is taken with rifampin and fluconazole. Glyburide is an oral drug commonly used to lower blood glucose levels in diabetic patients. Rifampin is an antibiotic used to treat tuberculosis and a variety of other infections caused by certain germs called bacteria. Both drugs affect a protein found in your liver cells called organic anion transporting polypeptides OATPs. This protein regulates drugs getting into and out of your body. Fluconazole is commonly used to treat fungal infections like candidiasis, urinary tract infections and a variety of other infections caused by fungi. It interacts with glyburide by affecting your bodys ability to breakdown glyburide. Since both rifampin and fluconazole play a role in the way glyburide enters and remains active in the body, we want to find out what effect taking the three drugs together has on the level of glyburide in the blood. 