Silymarin in the treatment of patients with primary biliary cirrhosis witha suboptimal response to ursodeoxycholic acid

Ursodeoxycholic acid (UDCA) is a safe and effective medical therapy for mos t patients with primary biliary cirrhosis (PBC), but some patients show an incomplete response. Silymarin is a potent antioxidant with immunomodulator y and antifibrotic properties. The aim of this study was to evaluate the sa fety and assess the efficacy of silymarin in patients with PBC who had show n a suboptimal response to UDCA. Twenty-seven patients with PBC who had bee n on UDCA (13-15 mg/kg/day) therapy for 7 to 221 months and had shown a per sistent elevation of alkaline phosphatase activity at least 2 times the upp er limit of normal for more than 6 months were enrolled. Oral silymarin, 14 0 mg 3 times daily was given for 1 year, and patients continued on the same dosage of UDCA, No significant changes in serum alkaline phosphatase activ ity (897 +/- 84 vs. 876 +/- 95, P =.5), total bilirubin (0.9 +/- 0.1 vs. 1 +/- 0.1, P = .07), aspartate transaminase (AST) (58 +/- 5 vs. 56 +/- 6, P = .4), albumin (4.0 +/- .06 vs. 4.1 +/- .06, P =.4), or Mayo risk score (3.82 +/- 0.2 vs. 3.88 +/- 0.2, P =.4) were noted after 1 year of treatment with combination therapy. Transitory gastrointestinal adverse events occurred i n 2 patients. In conclusion, although silymarin was well tolerated, this me dication did not provide benefit to patients with PBC responding suboptimal ly to UDCA. The results of this pilot study would seem to discourage furthe r controlled trials of silymarin in patients with PBC.