Adefovir dipivoxil in the treatment of chronic hepatitis B.

Abstract

To evaluate properties of the new acyclic nucleotide analog adefovir dipivoxil in the treatment of chronic hepatitis B (CHB). MEDLINE and PubMed searches from 1966 to December 2003 were performed with the headings chronic hepatitis B, interferon alfa-2b, lamivudine, liver transplant, and adefovir dipivoxil. Randomized controlled studies and meta-analyses were evaluated in detail. A manual search was performed using references from retrieved primary literature, review articles, editorials, postgraduate course syllabi from national meetings, and textbooks. Emphasis was placed on controlled, prospective, randomized trials. National meeting abstract presentations were included if the information offered was original. CHB is a major viral infection with an estimated 400 million carriers worldwide. Medications available to treat CHB include interferon alfa-2b and lamivudine, both agents having significant limitations. Adefovir dipivoxil is a novel nucleotide analog which, when given at 10 mg/day for 48 weeks, improved liver histology in 28% more patients with hepatitis B e antigen (HBeAg)-positive CHB, and in 31% more patients with HBeAg-negative CHB compared with placebo (p < 0.001). Additionally, adefovir dipivoxil therapy significantly improved virologic and biochemical parameters in both HBeAg-positive and -negative CHB patients. Adefovir dipivoxil offers important advantages over other CHB treatment options: it maintains activity against lamivudine-resistant CHB, has good efficacy against HBeAg-negative CHB, and has minimal adverse effects at the 10-mg/day Food and Drug Administration-approved dose. Approved medications for the treatment of CHB have many limitations, and adefovir dipivoxil provides a new important option as an initial treatment, as well as treatment in lamivudine-resistant patients.