Preparation for Liver Biopsy

Before scheduling your biopsy, the physician will take blood samples to make sure your blood clots properly. Be sure to mention any medications you take, especially those that affect blood clotting, like blood thinners. One week before the procedure, you will have to stop taking aspirin, ibuprofen, and anticoagulants.

You must not eat or drink anything for 8 hours before the biopsy, and you should plan to arrive at the hospital about an hour before the scheduled time of the procedure. Your physician will tell you whether to take your regular medications during the fasting period and may give you other special instructions.

source: http://digestive.niddk.nih.gov/ddiseases/pubs/liverbiopsy/index.htm