AST-120 Used to Treat Mild Hepatic Encephalopathy

Inclusion Criteria: 1. Confirmed cirrhosis of any cause 2. Abnormal RBANS global summary score 3. Grade 0 or 1 hepatic encephalopathy by West-Haven Scale 4. MELD score \< or = 25 5. Females must be postmenopausal, surgically incapable of bearing children or practicing a reliable method of birth control Exclusion Criteria: 1. Previous participation in any trial involving AST-120 2. History of TIPS or surgically created portocaval shunt 3. Treatment for overt HE within the past 3 months 4. Use of lactulose, rifaximin, neomycin or other antibiotics in the past 7 days 5. Active alcohol abuse 6. Psychosis or organic brain syndromes due to alcohol or other causes 7. Use of interferon and sedating or cognition-altering drugs 8. Undergoing chemotherapy or radiotherapy for the treatment of cancer 9. Active GI bleeding within the past 3 months 10. Presence of an active infection 11. Presence of signs and symptoms of severe dehydration 12. Other major physical or major psychiatric illness within the past 6 months 13. Pregnant, breast feeding, or planning to become pregnant during the study 14. Using hormonal contraception as the only method of birth control