Antiviral treatment of genital herpes

Antiviral therapy for genital herpes infections in pregnancy

One of the most deleterious consequences of maternal infection with herpes simplex virus is neonatal herpes, which results in death or significant neurodevelopmental impairment in the majority of infected babies. Herpes simplex virus infection during pregnancy can also impact the psychologic health of the mother. The ability to minimize the risk of herpes simplex virus transmission has improved in tandem with advances in understanding of the mechanisms and epidemiology of acquisition of neonatal herpes simplex virus. In particular, antiviral pharmacotherapy is now recognized as an important option both for reducing the risk of transmission of herpes simplex virus from a seropositive to a seronegative partner and, potentially, for modifying several risk factors for transmission of the virus from a herpes simplex virus-infected mother to the neonate. This review discusses the consequences and management of herpes simplex virus infection during pregnancy, with a focus on the evolving role of antiviral therapy.

Disposition kinetics of a dipeptide ester prodrug of acyclovir and its metabolites following intravenous and oral administrations in rat

The objective of this work was to study the disposition kinetics of valine-valine-acyclovir (VVACV), a dipeptide ester prodrug of acyclovir following intravenous and oral administrations in rat. A validated LC-MS/MS analytical method was developed for the analysis VVACV, Valine-Acyclovir (VACV), and Acyclovir (ACV) using a linear Ion Trap Quadrupole. ACV was administered orally for comparison purpose. In the VVACV group, both blood and urine samples and in the ACV group only blood samples were collected. All the samples were analyzed using LC-MS/MS. The LLOQ for ACV, VACV, and VVACV were 10, 10, and 50 ng/ml, respectively. Relevant pharmacokinetic parameters were obtained by non-compartmental analyses of data with WinNonlin. Following i.v. administration of VVACV, AUC(0-inf) (min*µM) values for VVACV, VACV, and ACV were 55.06, 106, and 466.96, respectively. The AUC obtained after oral administration of ACV was 178.8. However, following oral administration of VVACV, AUC(0-inf) values for VACV and ACV were 89.28 and 810.77, respectively. Thus the exposure of ACV obtained following oral administration of VVACV was almost 6-fold higher than ACV. This preclinical pharmacokinetic data revealed that VVACV has certainly improved the oral bioavailability of ACV and is an effective prodrug for oral delivery of ACV.

Single-day famciclovir therapy for recurrent genital herpes

BACKGROUND

Genital herpes is a lifelong incurable viral infection that can have a significant psychological and emotional impact on patients. A common therapy for treating recurrent outbreaks is the episodic use of nucleoside analogues for 3-5 days. However, since maximum viral replication occurs within 24 h after symptoms first appear, the best option may be short-term, patient-initiated episodic therapy, administered during the onset of prodromal symptoms. This commentary will examine the results of a recent clinical trial of patient-initiated episodic famciclovir therapy that is administered for a single day and compare efficacy data from that trial with data from trials of currently prescribed antiviral therapies.

FINDINGS

This recent trial that evaluated the efficacy of single-day famciclovir compared to placebo in the treatment of recurrent genital herpes found that famciclovir decreased time to lesion healing and duration of symptoms, and increased the proportion of patients who did not progress to a full outbreak. Although no head-to-head studies have been completed, single-day famciclovir therapy seems to provide improvement that is similar to or better than that associated with traditional longer-term treatments.

CONCLUSION

The increased convenience for the patient of single-day therapy may lead to improved patient compliance and better overall management of recurrent genital herpes outbreaks.

Single-day therapy for recurrent genital herpes

Genital herpes, an incurable viral disease that can have a devastating impact on affected patients, is a serious public health concern affecting one in four Americans. Episodic treatment with nucleoside analogs for 3-5 days is the most common method of treatment; however, since maximum viral replication occurs within 24 hours after the onset of symptoms, single-day patient-initiated episodic treatment may be a better option. A recent study evaluated the effectiveness of patient-initiated single-day famciclovir versus placebo in the treatment of genital herpes and found that single-day famciclovir decreased healing time and the duration of pain and other symptoms, and increased the proportion of patients who did not progress to a full outbreak. Compared with previous studies, the results of single-day therapy are similar to or better than the results of conventional therapies of 2-5 days' duration. In addition, the convenience of single-day treatment may lead to greater patient adherence and improved overall management of recurrent herpes outbreaks.

Achievements and challenges in antiviral drug discovery

The last 40 years have seen the development of several antiviral drugs with therapeutic value in treating life-threatening or debilitating diseases such as those caused by HIV, hepatitis B virus, herpesviruses (such as herpes simplex virus and varicella zoster virus) and influenza virus. These relatively recent advances have been due to technical breakthroughs in the cultivation of viruses in the laboratory, identification of viral enzymes and, more recently, their molecular biology. We describe here the antecedence of several of the existing antivirals and their strengths and weaknesses. We indicate where the major challenges lie for future improvements of current therapies and possible new indications, such as hepatitis C virus and papillomavirus. We also describe how current antiviral therapies are restricted to a rather limited number of viral diseases of sufficient interest to the pharmaceutical industry. Finally we describe the potential threat of emerging viruses and bio-weapons and the challenges that they present to therapy.

New management of the pregnant patient to reduce the risk of transmitting herpes to the newborn

Growing understanding of the mechanisms and epidemiology of neonatal herpes simplex virus acquisition allows for the development of a new management of the pregnant patient, one that will reduce the risk of transmitting herpes to the newborn. Maternal herpes simplex virus infection, especially acquired during pregnancy, can result in transmission to the newborn. Infection of the CNS of the newborn results in death or significant neurodevelopmental impairment in most of these infected babies. Herpes simplex virus infection acquired prior to or during pregnancy has a physical and psychologic impact on the health of the mother. Newer, more sensitive and specific serology testing for herpes simplex virus in combination with antiviral pharmacotherapy is now recognized as an important option for reducing the risk of herpes simplex virus transmission from mother to newborn. This review discusses new information concerning the prevention, diagnosis and treatment options for the management of herpes simplex virus infection during pregnancy with a focus on the evolving role of prevention.