Medical Content Created by the Faculty of the
Harvard Medical School
You will need to sign a consent form giving your doctor permission to perform this test. Because you will probably receive some pain medicines or anti-anxiety medications that can make you drowsy, you will need to arrange a ride home.
Tell your doctor if you have ever had an allergic reaction to lidocaine or the numbing medicine used at the dentist's office. Also talk with your doctor before the test if you are taking insulin, or if you take aspirin, nonsteroidal anti-inflammatory drugs, or other medicines that affect blood clotting. It may be necessary to stop or adjust the dose of these medicines before your test. Most people need to have a blood test done some time before the procedure to make sure they are not at high risk for bleeding complications.
Usually you will be told not to eat anything after midnight on the night before the test. This is in case you experience nausea from the anti-anxiety medicines.