Before you can start treatment on this study, you will have what are called "screening tests" no more than one week before starting the study. These tests will help the doctor decide if you are eligible to take part in the study. You will have a complete medical history and physical exam, including measurements of your weight, blood pressure, pulse, and temperature. You will also be asked what other medicines you are taking and about your general well-being. You will have an electrocardiogram (ECG - a test to measure the electrical activity of the heart). Blood (about 2 1/2 tablespoons) will be drawn. A sample of urine will be also be collected and tested to see if your kidneys are working correctly. Women who are able to have children must have a negative urine pregnancy test.