Valacyclovir Daily Dosing for Herpes Simplex Virus Infection
For an immunocompetent adult with normal renal function and HSV infection, the recommended daily dose of valacyclovir depends on the clinical scenario: 500 mg twice daily for 3 days for recurrent episodes, 1 gram twice daily for 10 days for initial episodes, or 500-1000 mg once daily for suppressive therapy. 1
Treatment of Active HSV Infection
Initial Episode of Genital Herpes
- Valacyclovir 1 gram orally twice daily for 10 days is the FDA-approved regimen for first episodes 1
- Therapy is most effective when initiated within 48 hours of symptom onset 1
- This dosing achieves equivalent efficacy to acyclovir 200 mg five times daily but with simpler administration 2, 3
Recurrent Episodes of Genital Herpes
- Valacyclovir 500 mg twice daily for 3 days is the recommended treatment 1
- Initiate at the first sign or symptom of recurrence 1
- Alternative regimens include 500 mg twice daily for 5 days, which demonstrates equivalent efficacy 2, 3
- A 1 gram twice daily dose provides no additional benefit over 500 mg twice daily for recurrent episodes 2
Cold Sores (Herpes Labialis)
- Valacyclovir 2 grams twice daily for 1 day (12 hours apart) is the FDA-approved regimen 1
- Treatment should begin at earliest symptoms (tingling, itching, burning) 1
Suppressive Therapy for Recurrent HSV
Standard Suppression in Immunocompetent Patients
- Valacyclovir 1 gram once daily is recommended for patients with frequent recurrences (≥10 episodes per year) 4, 1
- Valacyclovir 500 mg once daily is an acceptable alternative for patients with 9 or fewer recurrences per year 4, 1
- The 500 mg once daily dose is less effective in patients with very frequent recurrences and should be avoided in this population 4
- Daily suppressive therapy reduces recurrence frequency by ≥75% 4
- Safety and efficacy documented for up to 1 year with valacyclovir 4
Transmission Reduction
- Valacyclovir 500 mg once daily is recommended for source partners to reduce transmission risk 1
- This indication applies to patients with a history of 9 or fewer recurrences per year 1
HIV-Infected Patients
- Valacyclovir 500 mg twice daily is recommended for suppressive therapy in HIV-infected patients with CD4+ count ≥100 cells/mm³ 4, 1
- Higher dosing is appropriate for immunocompromised patients due to potentially more severe and frequent recurrences 4
Important Clinical Considerations
Renal Function Monitoring
- No dose adjustment is needed for creatinine clearance 30-49 mL/min 4
- For CrCl <30 mL/min, reduce to 500 mg every 24-48 hours 5
- For hemodialysis patients, administer 500 mg after each dialysis session 5
- No laboratory monitoring is required for patients on suppressive therapy unless substantial renal impairment exists 4
Treatment Duration and Reassessment
- After 1 year of continuous suppressive therapy, consider discussing discontinuation to reassess recurrence frequency, as recurrences may decrease over time 4
- Suppressive therapy reduces but does not eliminate asymptomatic viral shedding 4
Treatment Failure and Resistance
- If lesions persist after 7-10 days of appropriate valacyclovir therapy, consider HSV resistance 4, 6
- All acyclovir-resistant HSV strains are also resistant to valacyclovir 4, 6
- For acyclovir-resistant HSV, IV foscarnet 40 mg/kg every 8 hours until clinical resolution is the treatment of choice 4, 6
Safety Warnings
- Avoid valacyclovir doses of 8 grams per day in immunocompromised patients due to risk of thrombotic thrombocytopenic purpura/hemolytic uremic syndrome 4, 6
- Adequate hydration should be maintained to minimize nephrotoxicity risk 4, 6
- High-dose valacyclovir (8 g/day) has been associated with increased mortality in advanced HIV disease and should be avoided 7