What is the recommended dose of Valtrex (valacyclovir) for various indications?

Valacyclovir (Valtrex) Dosing Recommendations for Various Indications

The recommended dosage of valacyclovir (Valtrex) varies by indication, with specific regimens for cold sores, genital herpes, herpes zoster, and chickenpox, along with adjustments needed for renal impairment and special populations. 1

Adult Dosing Recommendations

Cold Sores (Herpes Labialis)

• 2 grams twice daily for 1 day (taken 12 hours apart)
• Initiate at earliest symptom (tingling, itching, burning) 1

Genital Herpes

1. Initial Episode

   • 1 gram twice daily for 10 days
   • Most effective when started within 48 hours of symptom onset 1

2. Recurrent Episodes

   • 500 mg twice daily for 3 days
   • Initiate at first sign/symptom of episode 1
   • Short-course therapy (1-3 days) should not be used in HIV-infected patients 2

3. Suppressive Therapy

   • Normal immune function: 1 gram once daily
   • Patients with ≤9 recurrences/year: 500 mg once daily
   • HIV-infected patients (CD4+ ≥100 cells/mm³): 500 mg twice daily 1, 2

4. Reduction of Transmission

   • 500 mg once daily for source partner with ≤9 recurrences/year 1

Herpes Zoster (Shingles)

• 1 gram three times daily for 7 days
• Initiate at earliest sign/symptom (most effective within 48 hours of rash onset) 1

Pediatric Dosing Recommendations

Cold Sores

• Ages ≥12 years: 2 grams twice daily for 1 day (12 hours apart)
• Initiate at earliest symptom 1

Chickenpox

• Ages 2 to <18 years: 20 mg/kg three times daily for 5 days
• Maximum dose: 1 gram three times daily
• Initiate at earliest sign/symptom 1

Dosage Adjustments for Renal Impairment

Indication	Normal Dose	CrCl 30-49 mL/min	CrCl 10-29 mL/min	CrCl <10 mL/min
Cold sores	2g BID x1 day	No reduction	1g q24h	500mg q24h
Genital herpes (recurrent)	500mg q12h	No reduction	500mg q24h	500mg q24h
Genital herpes suppression	1g q24h	No reduction	500mg q24h	500mg q24h
Genital herpes suppression (≤9 recurrences/yr)	500mg q24h	No reduction	500mg q48h	500mg q48h
HIV-infected patients	500mg q12h	No reduction	500mg q24h	500mg q24h
Herpes zoster	1g q8h	1g q12h	1g q24h	500mg q24h

• Hemodialysis patients should receive the recommended dose after hemodialysis 1

Special Considerations

HIV-Infected Patients

• Genital HSV infection: 5-14 days of treatment (not short-course therapy)
• Suppressive therapy: 500 mg twice daily (CD4+ ≥100 cells/mm³)
• May help decrease HIV concentration in plasma and genital secretions 2

Severe Mucocutaneous HSV Lesions

• Initial treatment with IV acyclovir recommended
• Switch to oral therapy after lesions begin to regress
• Continue until lesions completely heal 2

Treatment Failure

• Suspect resistance if lesions don't begin resolving within 7-10 days
• For acyclovir-resistant HSV, IV foscarnet is treatment of choice 2

Clinical Pearls

• Valacyclovir may be given without regard to meals 1
• For genital herpes, initiate treatment within 48 hours of symptom onset for maximum effectiveness 1
• Valacyclovir has better bioavailability than oral acyclovir, allowing for less frequent dosing 3
• For patients with frequent recurrences (≥10/year), higher doses or twice-daily regimens are more effective 4
• Monitor renal function in patients receiving high-dose IV therapy 2
• Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome has been reported with high-dose valacyclovir (8g/day) but not at doses used for HSV infection 2

By following these evidence-based dosing recommendations, clinicians can effectively manage various herpesvirus infections while minimizing adverse effects and optimizing patient outcomes.