- The patient is unwilling or unable to avoid, for 10 days before and 3 days after liver biopsies, medications or herbal supplements that are potentially hepatotoxic (eg, 3 hydroxy 3 methylglutaryl coenzyme A reductase inhibitors, erythromycin, valproic acid, antidepressants, kava, echinacea) or may cause or prolong bleeding (eg, anticoagulants, ibuprofen, aspirin, garlic supplements, ginkgo, ginseng).