Recommended Dosage of Valacyclovir for Empiric HSV Treatment
For empiric treatment of herpes simplex virus (HSV), valacyclovir should be dosed at 1 gram twice daily for 10 days for initial genital herpes episodes, 500 mg twice daily for 3 days for recurrent episodes, or 2 grams twice daily for 1 day (taken 12 hours apart) for cold sores (herpes labialis). 1
Dosing by HSV Type and Presentation
Initial Genital Herpes Episode
- Dose: 1 gram twice daily
- Duration: 10 days
- Timing: Most effective when started within 48 hours of symptom onset 1
Recurrent Genital Herpes Episodes
- Dose: 500 mg twice daily
- Duration: 3 days
- Timing: Start at first sign or symptom of an episode 1
- Alternative: 1 gram once daily has been shown to be equivalent to 500 mg twice daily 2
Cold Sores (Herpes Labialis)
- Dose: 2 grams twice daily
- Duration: 1 day (taken 12 hours apart)
- Timing: Initiate at earliest symptom (tingling, itching, or burning) 1
Suppressive Therapy Options
For patients with frequent recurrences (≥6 per year), suppressive therapy may be considered:
- Standard dose: 1 gram once daily 1
- Alternative dose: 500 mg once daily (for patients with ≤9 recurrences per year) 1
- For HIV-infected patients: 500 mg twice daily (if CD4+ count ≥100 cells/mm³) 3, 1
Special Considerations
Renal Dosing Adjustments
Dose adjustments are necessary based on creatinine clearance:
| Creatinine Clearance (mL/min) | Genital Herpes Recurrent | Genital Herpes Suppressive |
|---|---|---|
| ≥50 (normal) | 500 mg every 12 hours | 1 gram every 24 hours |
| 30-49 | No reduction | No reduction |
| 10-29 | 500 mg every 24 hours | 500 mg every 24 hours |
| <10 | 500 mg every 24 hours | 500 mg every 24 hours |
Administration
- May be given without regard to meals 1
- For pediatric patients ≥12 years with cold sores: 2 grams twice daily for 1 day 1
Clinical Pearls and Pitfalls
- Timing is critical: Initiate treatment at the earliest sign of prodrome or within 1 day of lesion onset for maximum effectiveness 3
- Patient education: Provide prescriptions for patients to keep on hand to enable prompt self-treatment at first symptoms 3
- Compliance advantage: Once-daily dosing (1 gram) has been shown to be as effective as twice-daily dosing (500 mg) for recurrent episodes, potentially improving adherence 2
- Common triggers: Advise patients that stress, sunlight, and physical trauma can trigger recurrences 3
- Transmission risk: Patients should be counseled that asymptomatic viral shedding can still lead to transmission even during treatment 3
- Efficacy: Valacyclovir has been shown to reduce viral shedding by 71% compared to placebo, including a 58% reduction in subclinical shedding 4
Valacyclovir provides improved bioavailability compared to acyclovir, allowing for less frequent dosing while maintaining similar efficacy and safety profiles 5, 6.