Recommended Daily Dose of Valtrex (Valacyclovir)
The recommended daily dose of Valtrex (valacyclovir) varies based on the specific indication, with standard dosages ranging from 500 mg to 3 grams per day depending on the condition being treated. 1
Dosing Recommendations by Indication
Herpes Simplex Virus (HSV) Infections
Cold Sores (Herpes Labialis)
- Adults and children ≥12 years: 2 grams twice daily for 1 day (taken 12 hours apart) 1
- Initiate at earliest symptom (tingling, itching, burning)
Genital Herpes
- Initial episode: 1 gram twice daily for 10 days 1
- Most effective when started within 48 hours of symptom onset
- Recurrent episodes: 500 mg twice daily for 3 days 1
- Start at first sign/symptom of episode
- Suppressive therapy:
- Reduction of transmission: 500 mg once daily for source partner 1
Herpes Zoster (Shingles)
- Standard dose: 1 gram three times daily for 7 days 1
- Most effective when started within 48 hours of rash onset
Chickenpox (in children)
- Ages 2 to <18 years: 20 mg/kg three times daily for 5 days (maximum 1 gram three times daily) 1
Dosage Adjustments for Renal Impairment
Valacyclovir requires dose adjustment in patients with renal dysfunction:
| Creatinine Clearance (mL/min) | Dose Adjustment |
|---|---|
| >30 | 500 mg every 24-48 hrs |
| <30 | 500 mg every 24-48 hrs |
| Hemodialysis | 500 mg after each dialysis session |
Administration Considerations
- Valtrex may be given without regard to meals 1
- For patients who cannot swallow tablets, an oral suspension can be prepared extemporaneously from 500 mg tablets 1
- The simplified twice-daily or once-daily dosing regimens of valacyclovir offer better compliance compared to the five-times-daily dosing of acyclovir 5, 6
Clinical Pearls
- Valacyclovir is a prodrug of acyclovir with significantly better oral bioavailability 7, 8
- For suppressive therapy, clinical trials have shown that once-daily valacyclovir (500 mg or 1 gram) effectively reduces recurrence of genital herpes 2
- Patients with frequent recurrences (≥10 per year) may benefit from higher dosing (1 gram once daily) 2
- Therapy should be initiated at the earliest sign or symptom for maximum effectiveness 1
Common Pitfalls to Avoid
- Underdosing in immunocompromised patients who often require higher doses or longer treatment durations
- Failing to adjust doses in patients with renal impairment
- Delaying treatment initiation, which reduces efficacy
- Not considering the frequency of recurrences when selecting suppressive therapy dosage
Valacyclovir is generally well-tolerated, with headache being the most commonly reported side effect at standard dosages 7.