Antiviral Recommendations for Herpes Exposure

Herpes simplex virus (HSVI and HSVII), or genital herpes, is the most common sexually transmitted infection in the United States. Over 1 million new cases occur annually; at least 50 million people in the U.S. are infected with genital herpes. Many with milder symptoms are undiagnosed. Painful blisters, swelling, itching and fever are typically experienced with the first outbreak. The U.S. Preventative Services Task Force (USPSTF) recommends that "most patients with initial genital herpes should receive antiviral therapy."

Prevention

• Antiviral therapy is not recommended by the USPSTF for "persons who do not have clinical manifestations of infection." Sex partners of those who have genital herpes should be informed and educated to recognize symptoms and be offered testing for infection. Latex condoms are effective in reducing the spread of genital herpes. HSV can be transmitted from mouth to genitals, and pregnant women with HSV can pass the infection to their infant before, during or after delivery.
  Herpes virus poses a serious risk to newborns; long-term damage to the central nervous system or even death can occur. Danger is greatest if delivery takes place during the mother's initial outbreak, and cesarean delivery may be advised. According to Dr. Jean Malkin in "Herpes," subsequent outbreaks are much less likely to result in transmission--4 percent or less compared with up to a 50 percent transmission rate during primary outbreak. Mothers who are known to be infected with HSV may be given suppressive antiviral therapy during the last three months of pregnancy, but the USPSTF admits that "there is limited evidence of safety of antiviral treatments during pregnancy."

Antiviral Chemotherapy Agents

• The first medication approved for treatment of genital herpes infection was acyclovir. It effectively reduces pain and shortens the time that HSV blisters take to crust and heal. Acyclovir when used in pregnancy crosses the placenta, concentrates in amniotic fluid and goes through breast milk after birth. It is a pregnancy category C medication--for use only when benefits outweigh risks.
  Famciclovir and valacyclovir have a longer half life and greater bioavailability, respectively, so that both are more effective at lower doses than acyclovir. Expense and availability can influence the choice of prescribed antivirals.

Supressive Therapy

• Medications do not eradicate the virus, which is recurrent and lifelong. Antiviral chemotherapy benefits patients by controlling symptoms and signs of infection and shortening the course of outbreaks. When the drugs are discontinued, they do not affect the frequency or severity of episodes. However, most infections become less severe with time, so it is recommended that doctors discuss discontinuation of antiviral medications with their patients on suppressive therapy at least annually. Continuous suppressive therapy with antiviral drugs reduces the frequency of recurrences by 70 to 80 percent, according to studies reviewed by the USPSTF, but does not eliminate the possibility of transmission. Viral cells are still present and can infect partners, though to what degree is unknown.

Episodic Therapy

• The USPSTF found benefits to episodic therapy with antivirals, or the administration of drugs only during recurrence of HSV symptoms. Patients are prescribed a course of therapy to have on hand so that time is not wasted making appointments to obtain treatment. To be effective, medications should be started at the first sign of outbreak. The USPSTF pointed to studies that found a three-day course of twice daily valacyclovir as effective as a five-day course in treating HSV recurrence. Shortened durations of other medications were not studied.