Valtrex (Valacyclovir) Dosage for Genital Herpes, Cold Sores, and Shingles
The FDA-approved dosage of Valtrex (valacyclovir) is 2 grams twice daily for 1 day for cold sores, 1 gram twice daily for 10 days for initial genital herpes episodes, 500 mg twice daily for 3 days for recurrent genital herpes episodes, and 1 gram three times daily for 7 days for herpes zoster (shingles). 1
Cold Sores (Herpes Labialis)
- Dosage: 2 grams twice daily for 1 day (taken 12 hours apart) 1
- Treatment should be initiated at the earliest symptom (tingling, itching, or burning)
- Same dosage applies to adults and children ≥12 years of age
Genital Herpes
Initial Episode
- Dosage: 1 gram twice daily for 10 days 1
- Most effective when started within 48 hours of symptom onset
Recurrent Episodes
- Dosage: 500 mg twice daily for 3 days 1
- Initiate at first sign or symptom of an episode
- Alternative regimen: 1 gram once daily for 5 days has been shown to be equally effective 2
- A shorter 3-day course has been demonstrated to be equivalent to a 5-day course in efficacy 3
Suppressive Therapy
- Dosage for normal immune function: 1 gram once daily 1
- For patients with ≤9 recurrences per year: 500 mg once daily 1, 4
- For HIV-infected patients with CD4+ count ≥100 cells/mm³: 500 mg twice daily 1
Reduction of Transmission
- Dosage: 500 mg once daily for the source partner (with history of ≤9 recurrences per year) 1
Herpes Zoster (Shingles)
- Dosage: 1 gram three times daily for 7 days 1
- Therapy should be initiated at earliest sign or symptom
- Most effective when started within 48 hours of rash onset
Special Populations and Considerations
Pediatric Patients
- Cold sores: Same as adult dosage for children ≥12 years
- Chickenpox: For immunocompetent children 2 to <18 years: 20 mg/kg three times daily for 5 days (not to exceed 1 gram three times daily) 1
Renal Impairment
- Dosage adjustments required based on creatinine clearance 5
- For patients with severe renal impairment, consult specific dosing guidelines
Immunocompromised Patients
- May require longer treatment courses and closer monitoring 5
- For severe cases requiring hospitalization, IV acyclovir may be preferred 5
Patient Education
- Advise patients to:
- Abstain from sexual activity while lesions are present
- Be aware of asymptomatic viral shedding and potential for transmission
- Use condoms consistently during all sexual exposures 5
- Complete the full course of medication even if symptoms improve
- Initiate treatment at the earliest symptoms for best results
Clinical Pearls
- Valacyclovir is a prodrug of acyclovir with better oral bioavailability, allowing for less frequent dosing 6
- For genital herpes suppression, once-daily valacyclovir regimens offer a convenient option for patients requiring long-term therapy 4
- For patients with frequent recurrences (≥10 per year), higher dosages (1 gram daily) may be more effective 4
- Treatment is most effective when initiated within 48 hours of symptom onset
By following these dosage recommendations, clinicians can effectively manage herpes infections while minimizing recurrences and improving patient quality of life.