Valacyclovir Dosing for Genital Herpes
Initial Episode
For the first episode of genital herpes, treat with valacyclovir 1 gram twice daily for 10 days, starting within 48 hours of symptom onset for maximum effectiveness. 1
Recurrent Episodes
For recurrent genital herpes outbreaks, use valacyclovir 500 mg twice daily for 3 days, initiated at the first sign or symptom of an episode. 1
- This shorter 3-day course is sufficient for recurrent episodes, unlike the 10-day course needed for initial infection 1
- Treatment should begin immediately when prodromal symptoms appear (tingling, itching, burning) 1
- Alternative dosing of 1000 mg twice daily for 5 days has also shown efficacy in clinical trials 2
Suppressive Therapy (Chronic Prevention)
For Immunocompetent Patients
The standard suppressive dose is 1 gram once daily for patients with normal immune function. 1
- For patients with ≤9 recurrences per year, 500 mg once daily is an acceptable alternative 1, 3
- However, 500 mg once daily is less effective in patients with ≥10 recurrences per year, who should receive 1000 mg once daily 3, 4
- Suppressive therapy reduces recurrence frequency by ≥75% 3, 5
- Safety and efficacy documented for up to 1 year with valacyclovir 3
For HIV-Infected Patients
HIV-infected patients with CD4+ count ≥100 cells/mm³ require 500 mg twice daily (not once daily) for suppressive therapy. 1, 3, 6
- The twice-daily dosing is critical in this population due to potentially more severe and frequent recurrences 3
- This regimen has been shown to be as effective as acyclovir 400 mg twice daily in HIV-infected patients 6
Transmission Reduction
For reducing transmission to an uninfected partner, the source partner should take 500 mg once daily (for those with ≤9 recurrences per year). 1
Duration Considerations
- After 1 year of continuous suppressive therapy, consider discontinuing to reassess recurrence frequency, as recurrences often decrease over time 3, 5
- No laboratory monitoring is needed unless substantial renal impairment exists 3, 5
Important Clinical Caveats
- Valacyclovir can be taken without regard to meals 1
- Suppressive therapy reduces but does not eliminate asymptomatic viral shedding, so transmission risk remains 3, 5
- If lesions persist beyond 7-10 days despite appropriate treatment, suspect HSV resistance—all acyclovir-resistant strains are also valacyclovir-resistant, requiring IV foscarnet instead 3
- Avoid 8 grams per day dosing in immunocompromised patients due to risk of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome 3, 7
- For patients with CrCl 30-49 mL/min, no dose reduction is needed, but lower creatinine clearance requires adjustment 3