What is the treatment for primary genital Herpes Simplex Virus (HSV) infection?

Treatment of Primary Genital HSV Infection

For first-episode genital herpes, initiate oral antiviral therapy with valacyclovir 1 gram twice daily for 7-10 days, starting as soon as possible after symptom onset. 1

First-Line Treatment Regimens

The CDC recommends several equally effective options for primary genital herpes, all administered for 7-10 days: 1

• Valacyclovir 1 g orally twice daily (preferred due to convenient dosing)
• Acyclovir 400 mg orally three times daily
• Acyclovir 200 mg orally five times daily
• Famciclovir 250 mg orally three times daily

Treatment duration may be extended beyond 10 days if healing remains incomplete. 1

Critical Timing Considerations

• Initiate therapy within 72 hours of lesion onset for maximum effectiveness 1
• Treatment is most beneficial when started during the prodromal period or within 24 hours of first symptoms 2
• Delayed treatment beyond 72 hours significantly reduces therapeutic benefit 1

What NOT to Do

Topical acyclovir is substantially less effective than systemic therapy and should not be used. 1, 2 While topical formulations may provide some local benefit, they fail to address systemic symptoms or reduce viral shedding effectively. 3

Clinical Trial Evidence

In a randomized trial of 643 immunocompetent adults with first-episode genital herpes, valacyclovir 1 gram twice daily for 10 days demonstrated equivalent efficacy to acyclovir 200 mg five times daily, with median time to lesion healing of 9 days, cessation of pain at 5 days, and cessation of viral shedding at 3 days for both regimens. 4

Important Counseling Points

After initiating treatment, patients must understand: 1

• Genital herpes is a chronic, incurable viral infection
• Antiviral medications control symptoms but do not eradicate latent virus
• Recurrences are common, particularly with HSV-2
• Asymptomatic viral shedding can occur and lead to transmission
• Abstain from sexual activity when lesions or prodromal symptoms are present
• Consistent condom use reduces but does not eliminate transmission risk

Planning for Recurrences

Provide patients with a prescription for episodic therapy (valacyclovir 500 mg twice daily for 5 days) to self-initiate at the first sign of recurrence. 2 This allows for rapid treatment initiation, which is critical for effectiveness. 1

For patients who develop ≥6 recurrences per year, consider daily suppressive therapy with valacyclovir 1 gram once daily or 500 mg once daily, which can reduce recurrence frequency by ≥75%. 1

Special Populations

HIV-infected patients may require longer treatment courses and closer monitoring than HIV-negative patients. 1 In immunocompromised hosts, acyclovir resistance is an increasing concern, and treatment failure should prompt viral culture with susceptibility testing. 1

For pregnant women, systemic acyclovir and valacyclovir are generally considered safe, though definitive safety data are limited. 1 Ciprofloxacin is contraindicated during pregnancy. 1

Monitoring Treatment Response

If lesions do not begin to resolve within 7-10 days of initiating therapy, consider: 1

• Incorrect diagnosis
• Co-infection with another STD
• HIV infection
• Poor medication adherence
• Antiviral resistance (rare in immunocompetent hosts)

For confirmed acyclovir-resistant HSV, IV foscarnet 40 mg/kg every 8 hours is the treatment of choice. 1