Valacyclovir Suppression for Genital Herpes
Recommended Dosing Regimens
For suppressive therapy of recurrent genital herpes, valacyclovir 500 mg once daily is recommended for patients with fewer than 10 recurrences per year, while 1,000 mg once daily is recommended for those with 10 or more recurrences annually. 1, 2, 3
Standard Dosing for Immunocompetent Patients
- Patients with <10 recurrences per year: Valacyclovir 500 mg once daily 1, 2, 3, 4
- Patients with ≥10 recurrences per year: Valacyclovir 1,000 mg once daily OR 250 mg twice daily 1, 2, 3, 4
- The 500 mg once-daily regimen appears less effective in patients with very frequent recurrences (≥10 episodes per year), making higher doses necessary 5, 1, 6
Alternative Dosing Options
- Valacyclovir 250 mg twice daily is an effective alternative regimen 5, 6
- All valacyclovir dosing regimens demonstrate a dose-response relationship, with higher doses providing better suppression in patients with frequent recurrences 4
Duration and Long-Term Safety
Safety and efficacy of valacyclovir for suppressive therapy have been documented for 1 year of continuous use in immunocompetent patients. 1, 2, 6
- After 1 year of continuous suppressive therapy, discontinuation should be discussed to reassess the patient's current recurrence rate, as recurrence frequency often decreases over time in many patients 5, 1, 6
- Long-term studies demonstrate that valacyclovir is well-tolerated with no clinically significant resistance emerging in immunocompetent patients 1, 7
- No laboratory monitoring is required unless the patient has substantial renal impairment 2, 6
Clinical Benefits
- Daily suppressive therapy reduces recurrence frequency by ≥75% in patients with frequent outbreaks (≥6 recurrences per year) 1, 6
- Reduces asymptomatic viral shedding, though does not eliminate it completely 5, 1, 6
- Improves quality of life by preventing physical discomfort, psychological distress, and social impact of recurrent outbreaks 1
- Once-daily dosing improves adherence compared to more frequent acyclovir regimens (400 mg twice daily) 1, 4
Special Populations
HIV-Infected Patients
For HIV-infected patients with CD4+ count ≥100 cells/mm³, valacyclovir 500 mg twice daily (not once daily) is recommended for suppressive therapy. 2, 6, 3, 8
- Immunocompromised patients may experience prolonged and/or severe episodes of genital or perianal herpes 5, 1
- Higher doses are necessary due to potentially more severe and frequent recurrences 2
- Valacyclovir 500 mg twice daily has been shown effective in decreasing both recurrence rates and subclinical shedding in HIV-infected patients 8
Critical Safety Warning for Immunocompromised Patients
- Avoid valacyclovir doses of 8 g per day in immunocompromised patients due to risk of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome 5, 2, 7
- This serious adverse event has not been reported at standard suppressive doses (500 mg to 1,000 mg daily) 2, 6
Renal Dosing Adjustments
- For patients with creatinine clearance 30-49 mL/min, no dose reduction is needed for standard suppressive regimens 2
- Patients with substantial renal impairment require monitoring and potential dose adjustment 2
Important Counseling Points
- Suppressive therapy does not eradicate the virus or completely prevent transmission—asymptomatic viral shedding can still occur 5, 1, 6
- Patients should be counseled that while suppressive therapy significantly reduces outbreak frequency and viral shedding, safe sex practices remain essential 1, 6
- The extent to which suppressive therapy prevents HSV transmission to partners is reduced but not eliminated 5
Treatment Failure and Resistance
- If lesions persist after 7-10 days of appropriate valacyclovir therapy, consider HSV resistance 2, 6
- All acyclovir-resistant strains are also resistant to valacyclovir 2
- For acyclovir-resistant HSV, IV foscarnet (40 mg/kg every 8 hours until clinical resolution) is the treatment of choice 2
- Resistance is rare in immunocompetent patients but more common in immunocompromised individuals 6