Drug update: genital herpes simplex virus.(Gynecology)

Three oral antiviral medications are approved to treat genital herpes simplex virus infections: acyclovir, famciclovir, and valacyclovir. The drugs are equally effective and well tolerated, with rare side effects consisting mainly of mild headache or nausea. That makes cost and convenience important in choosing among them.

For recurrent episodes, educate patients to start therapy within 1 day of lesion onset or during the prodrome that precedes some outbreaks, or to consider chronic suppressive therapy. Suppressive therapy reduces the frequency of genital herpes recurrences by 80% in patients with six or more outbreaks per year. Rather than recommending suppressive therapy on the basis of the number of HSV recurrences per year, talk to patients about their concerns and preferences. Even a few outbreaks can be psychologically distressing to some patients. In general, suppressive therapy is underused. Reevaluate suppressive therapy after 1 year, because recurrences tend to decrease over time. Suppressive therapy also cuts the risk of transmission by about half, based on recent study results.

Treat HSV-related pain with analgesics. Sitz baths may help. For women with external dysuria caused by HSV, sitting in a tub of warm water to urinate may be more comfortable. Topical antivirals are not recommended for genital HSV, owing to lack of efficacy and an association in one study with emergence of resistant virus.

For severe genital HSV disease or for patients who are hospitalized for complications such as disseminated infection, consider intravenous acyclovir therapy. Use oral antiviral therapy after that if necessary for a total of 10 days of treatment.

Drug-resistant HSV is rare; it generally occurs in immunocompromised patients. Resistance to one anti-HSV drug confers resistance to all. Consider foscarnet therapy in patients with laboratory-documented resistant HSV. Another option is topical cidofovir. Treating HIV-infected patients is especially important because HIV can be transmitted via herpes lesions.

All HSV antivirals can be used in the elderly. Use lower doses for patients with severe renal compromise. These drugs are classified as pregnancy category B; their safety is not proved, so they are not routinely recommended in the first trimester. However, extensive experience with acyclovir supports its safety in pregnancy and lactation. Famciclovir is probably safe in pregnancy, but the data are very limited compared with the other two agents. Most experts recommend that women with genital herpes lesions at the onset of labor be delivered by C-section to avoid neonatal transmission. Preliminary evidence suggests that giving acyclovir late in pregnancy to women with a history of recurrent herpes may reduce recurrences at term and lower the need for C-section.

Counseling is critical for HSV management. Plan for multiple follow-up appointments to address patient concerns, discuss transmission risks, and provide educational resources. Recommendations in this Drug Update are similar to those from the Centers for Disease Control and Prevention (MMWR 51[RR-06]:1-80, 2002).