valacyclovir and sorivudine

The antiherpes drugs, aciclovir and ganciclovir, are considered the standard treatments and prophylactic agents for infections caused by herpes simplex virus (HSV), varicella zoster virus (VZV) and cytomegalovirus (CMV). Until a decade ago, the impact of aciclovir on the control of severe and life-threatening herpesvirus infections was unprecedented. During the past few years, we have witnessed approval of new therapeutic drugs for infections caused by HSV and VZV (i.e. penciclovir and the oral prodrugs, valaciclovir and famciclovir), CMV (i.e. ganciclovir, cidofovir and fomivirsen) or HSV, VZV and CMV (i.e. foscarnet). A few agents, such as brivudin and benzimidavir, are in ongoing clinical development; others have been suspended because of safety concerns. New antiherpes agents are needed to face clinical issues such as drug resistance, increased use of antiherpes prophylaxis in transplantation and safety concerns in small children or pregnant women.

Topics: 2-Aminopurine; Acyclovir; Antiviral Agents; Arabinofuranosyluracil; Bromodeoxyuridine; Cidofovir; Clinical Trials as Topic; Cytosine; Famciclovir; Foscarnet; Ganciclovir; Guanine; Herpesviridae Infections; Humans; Organophosphonates; Organophosphorus Compounds; Thionucleotides; Valacyclovir; Valine

The character of diseases caused by alphaherpesviruses has changed over the last decade. The severity of disease and the frequency of acyclovir resistance has increased with the increase in the number of immunocompromised patients. Compounding the trend towards more virulent herpes disease is the current emphasis towards outpatient management of many diseases. Much of the current antiviral research focuses on providing drugs with (i) improved oral bioavailability and pharmacokinetics which permit less frequent oral or topical dosing for suppressive treatment of herpes simplex virus (HSV) infections, (ii) different mechanisms of action for synergic effects in treating resistant HSV infections in the immunocompromised host and (iii) improved efficacy. Future antiviral agents will probably target enzymes or viral factors essential for infection or will inhibit other steps in the viral infection cycle, such as viral entry, protein synthesis or capsid assembly. Medications that augment the immune response constitute another pathway for combating herpes viral infections. Many of the newer experimental agents target essential processes unique to herpesvirus replication and, therefore, potentially have high selectivity.

Topics: 2-Aminopurine; Acyclovir; Alphaherpesvirinae; Antibodies, Monoclonal; Arabinofuranosyluracil; Cidofovir; Cytosine; Famciclovir; Guanine; Herpesviridae Infections; Humans; Organophosphonates; Organophosphorus Compounds; Valacyclovir; Valine

Antiviral treatment of herpesvirus infections is rapidly changing since the advent of new drugs with improved oral availability. The efficacy of valaciclovir, the prodrug of aciclovir, and famciclovir, the prodrug of penciclovir, in the treatment of herpes genitalis and acute herpes zoster has been well documented in large clinical trials. Both drugs are effective on zoster-associated pain. Brivudin and sorivudine which are the most active compounds against varicella-zoster virus (VZV) in cell culture have also been successful in the treatment of herpes zoster. Aciclovir is still the standard therapy of severe herpes simplex virus (HSV) and varicella virus infections. In patients treated with aciclovir, the mortality of herpes encephalitis has been reduced to about 25%. The development of resistance against aciclovir and the other nucleoside analogues has not been a problem to date in the treatment of immunocompetent individuals. However, in immunocompromised patients, aciclovir-resistant HSV strains often emerge. In such cases, intravenous foscarnet is the current treatment of choice.

Topics: 2-Aminopurine; Acyclovir; Administration, Oral; Antiviral Agents; Arabinofuranosyluracil; Bromodeoxyuridine; Chickenpox; Drug Resistance, Microbial; Encephalitis, Viral; Famciclovir; Herpes Genitalis; Herpes Labialis; Herpes Simplex; Herpes Zoster; Humans; Immunocompromised Host; Prodrugs; Simplexvirus; Valacyclovir; Valine

Topics: 2-Aminopurine; Acyclovir; Antiviral Agents; Arabinofuranosyluracil; Chickenpox; Drug Resistance, Microbial; Famciclovir; Herpes Simplex; Herpes Zoster; Humans; Valacyclovir; Valine

Herpes zoster is a serious medical problem, not only because of the discomfort associated with the acute rash, but also because of the potential for post-herpetic neuralgia. Acyclovir is currently the antiviral drug of choice for the treatment of herpes zoster. Efforts are underway to develop new drugs that have improved activity against varicella-zoster virus as well as more favorable pharmacokinetic properties. The goal of these efforts is to develop an orally administered antiviral drug that will accelerate the events of cutaneous healing as well as reduce the frequency and severity of post-herpetic neuralgia. Investigational drugs currently under evaluation include valaciclovir and famciclovir, the prodrugs of acyclovir and penciclovir, respectively. Two new uracil derivatives, sorivudine and BW882C87, with increased anti-varicella-zoster virus activity in vitro are also being studied.

Topics: 2-Aminopurine; Acyclovir; Antiviral Agents; Arabinofuranosyluracil; Drugs, Investigational; Famciclovir; Herpes Zoster; Humans; Prodrugs; Valacyclovir; Valine

The signs, symptoms, diagnoses, and treatment of human herpesviruses are discussed, including advances and refinements in treatment options. Various treatment drugs, such as Zovirax, Famvir, Cidofovir, Foscarnet, Valtrex, and Virend, are examined. Genital herpes vaccines and possible alternative therapies are reviewed. In particular, varicella zoster virus, the virus that produces chicken pox and shingles, is examined, including its signs, symptoms, and intervention strategies using famciclovir and sorivudine. Final comments discuss the Epstein-Barr virus, the cause of mononucleosis, the newly discovered human herpesviruses, and the future prospects for identifying and appropriately treating herpesviruses.

Topics: 2-Aminopurine; Acyclovir; Antiviral Agents; Arabinofuranosyluracil; Cidofovir; Complementary Therapies; Cytosine; Famciclovir; Foscarnet; Herpesviridae Infections; Organophosphonates; Organophosphorus Compounds; Valacyclovir; Valine; Viral Vaccines