Minocycline in Primary Sclerosing Cholangitis (PSC)

Inclusion Criteria: * Both genders * Females of childbearing age must have negative pregnancy test within 48 hours of participation and agreement to practice contraception for the duration of the study. * Age 18 years old and \< than 75 years old. * History of chronic cholestatic disease of at least 6 months duration. * Serum alkaline phosphatase level at least 1.5 times the upper limit of normal. * Cholangiography demonstrating intrahepatic and/or extrahepatic biliary obstruction, beading, or narrowing consistent with PSC. * Liver biopsy consistent with the diagnosis of PSC. * Patient's informed consent for study participation. Exclusion Criteria: * Treatment with tetracyclines, ursodeoxycholic acid, corticosteroids, colchicine, methotrexate, azathioprine, cyclosporine, chlorambucil, budesonide, pentoxifylline, pirfenidone, nicotine, tacrolimus, silymarin, vitamin E or prednisone in the preceding three months. * Findings highly suggestive of hepatobiliary disease of other etiology complicating PSC. * Anticipated need for liver transplantation in one year determined by the Mayo model with an estimate of \<75% one year survival without transplantation. * Recurrent variceal bleeding, presence of ascites, or encephalopathy. * Active drug or alcohol use. * Pregnancy. * Breast-feeding. * Serum creatinine over 1.5 mg/dl. * Prior history of allergic reactions to antibiotics belonging to the tetracycline family. * Any condition that, in the opinion of the investigator, would interfere with the patient's ability to complete the study safely or successfully. * Patients with active inflammatory bowel disease (IBD) requiring specific treatment in the preceding three months, except for maintenance therapy with 5-ASA compounds, or those individuals who have been involved in a trial evaluating any experimental drug for the treatment of IBD in the preceding three months. * Recurrent ascending cholangitis requiring hospitalization in the past year.