valacyclovir and Hepatitis-B--Chronic

Most viral diseases, with the exception of those caused by human immunodeficiency virus, are self-limited illnesses that do not require specific antiviral therapy. The currently available antiviral drugs target 3 main groups of viruses: herpes, hepatitis, and influenza viruses. With the exception of the antisense molecule fomivirsen, all antiherpes drugs inhibit viral replication by serving as competitive substrates for viral DNA polymerase. Drugs for the treatment of influenza inhibit the ion channel M(2) protein or the enzyme neuraminidase. Combination therapy with Interferon-α and ribavirin remains the backbone treatment for chronic hepatitis C; the addition of serine protease inhibitors improves the treatment outcome of patients infected with hepatitis C virus genotype 1. Chronic hepatitis B can be treated with interferon or a combination of nucleos(t)ide analogues. Notably, almost all the nucleos(t) ide analogues for the treatment of chronic hepatitis B possess anti-human immunodeficiency virus properties, and they inhibit replication of hepatitis B virus by serving as competitive substrates for its DNA polymerase. Some antiviral drugs possess multiple potential clinical applications, such as ribavirin for the treatment of chronic hepatitis C and respiratory syncytial virus and cidofovir for the treatment of cytomegalovirus and other DNA viruses. Drug resistance is an emerging threat to the clinical utility of antiviral drugs. The major mechanisms for drug resistance are mutations in the viral DNA polymerase gene or in genes that encode for the viral kinases required for the activation of certain drugs such as acyclovir and ganciclovir. Widespread antiviral resistance has limited the clinical utility of M(2) inhibitors for the prevention and treatment of influenza infections. This article provides an overview of clinically available antiviral drugs for the primary care physician, with a special focus on pharmacology, clinical uses, and adverse effects.

Topics: Acyclovir; Adenine; Amantadine; Antiviral Agents; Comorbidity; Drug Therapy, Combination; Foscarnet; Ganciclovir; Guanine; Hepatitis; Hepatitis B, Chronic; Hepatitis C; Herpesviridae Infections; HIV Infections; Humans; Influenza, Human; Interferons; Lamivudine; Nucleosides; Oligopeptides; Organophosphonates; Oseltamivir; Proline; Protease Inhibitors; Pyrimidinones; Ribavirin; Telbivudine; Thymidine; Valacyclovir; Valganciclovir; Valine; Virus Replication; Zanamivir

We report on a chronic asymptomatic hepatitis B surface antigen (HBsAg) carrier who developed an increase in aminotransferase and HBsAg levels 1 year after lung transplantation. During treatment for cutaneous herpes simplex virus (HSV) infection with oral valaciclovir there was a marked decrease in replicating hepatitis B virus (HBV)-DNA and aminotransferase levels, which was sustained for 9 months by continuing low-dose valaciclovir. A second rise in aminotransferase levels again responded to a valaciclovir dose increase and the HBV-DNA levels declined further. Although we cannot exclude a spontaneous variation of the serologic parameters, our observation suggests that valaciclovir may represent a valuable therapeutic option in the treatment of chronic hepatitis B after lung transplantation.

Topics: Acyclovir; Bronchiectasis; Carrier State; Chronic Disease; Female; Follow-Up Studies; Graft Survival; Hepatitis B Surface Antigens; Hepatitis B, Chronic; Humans; Lung Transplantation; Middle Aged; Postoperative Complications; Preoperative Care; Risk Assessment; Serologic Tests; Treatment Outcome; Valacyclovir; Valine