Valacyclovir (Valtrex) Dosing for Acute Genital Herpes Outbreak
The recommended dosing of Valtrex (valacyclovir) for an acute outbreak of genital herpes is 500 mg twice daily for 3 days, initiated at the first sign or symptom of an episode. 1
Dosing Recommendations Based on Type of Episode
Initial Episode
- Dosage: 1 gram twice daily
- Duration: 10 days
- Note: Most effective when started within 48 hours of symptom onset 1
Recurrent Episodes
- Dosage: 500 mg twice daily
- Duration: 3 days
- Note: Treatment should be initiated at the first sign or symptom of an outbreak (tingling, itching, burning) 1
Treatment Efficacy
Valacyclovir provides several advantages over older treatments:
- Simpler administration schedule compared to acyclovir (which requires dosing five times daily) 2
- Equivalent efficacy to acyclovir with fewer daily doses 2
- Better oral bioavailability than acyclovir 3
Alternative Dosing Option
A once-daily alternative has been studied:
- 1000 mg once daily for 5 days has been shown to be equivalent to 500 mg twice daily for recurrent episodes 4
- This may offer improved convenience and adherence for some patients
Suppressive Therapy Options
For patients with frequent recurrences (≥9 per year), suppressive therapy may be considered:
- Standard dosage: 1 gram once daily 1
- Alternative for patients with ≤9 recurrences per year: 500 mg once daily 1, 5
- For HIV-infected patients with CD4+ count ≥100 cells/mm³: 500 mg twice daily 1
Important Clinical Considerations
- Initiate treatment as early as possible at the first sign of an outbreak for maximum effectiveness
- Valacyclovir can be taken without regard to meals 1
- For patients with renal impairment, dose adjustment may be necessary
- Headache is the most commonly reported side effect 3
Common Pitfalls to Avoid
- Delayed initiation of therapy: Treatment is most effective when started within the first 24-48 hours of symptom onset
- Inadequate duration: Complete the full course of therapy even if symptoms improve
- Confusing dosing for different indications: The 2 gram twice daily for 1 day dosing is for cold sores (herpes labialis), not genital herpes 1
- Failing to consider suppressive therapy: For patients with frequent recurrences (≥4 per year), discuss the option of daily suppressive therapy
Valacyclovir is well-tolerated at the recommended dosages for treatment of genital herpes outbreaks, with safety profiles comparable to placebo in clinical trials 5, 6.