Valacyclovir Dosing for Recurrent Cold Sores
For recurrent cold sores (herpes labialis) in immunocompetent adults, the recommended valacyclovir dose is 2 grams twice daily for 1 day, with doses taken 12 hours apart. 1, 2
Treatment Regimen
- Dose: 2 grams orally, repeated once after 12 hours (total treatment duration: 1 day) 1, 2
- Timing: Initiate therapy at the earliest symptom of a cold sore—during the prodromal phase when experiencing tingling, itching, or burning 1, 3
- Maximum effectiveness: Treatment must begin within 24 hours of symptom onset for optimal results 3
Evidence Supporting This Regimen
The American College of Obstetricians and Gynecologists specifically recommends this high-dose, short-duration regimen (2 grams twice daily for 1 day, taken 12 hours apart) for oral herpes 1. This recommendation is supported by two large randomized, placebo-controlled trials demonstrating that this 1-day regimen:
- Reduces median episode duration by 1.0 day compared to placebo (p=0.001) 4
- Accelerates healing time and decreases lesion-associated pain 3, 4
- Prevents or blocks cold sore lesion development in a higher proportion of patients 4
- Provides a more convenient alternative to the longer treatment courses required for genital herpes 4
Clinical Advantages
- Superior bioavailability: Valacyclovir delivers 3-5 times better acyclovir bioavailability than oral acyclovir, enabling effective treatment with less frequent dosing 4, 5
- Convenience: The 1-day regimen offers significantly simpler administration compared to acyclovir (which requires 5 doses daily) or topical therapies 4, 5
- Well-tolerated: Adverse events are similar to placebo, with headache being the most commonly reported side effect 3, 6
Critical Pitfalls to Avoid
- Do not confuse with genital herpes dosing: The recurrent genital herpes dose is 500 mg twice daily for 3-5 days—this is inadequate for cold sores 1, 2
- Do not delay treatment: Efficacy drops significantly if treatment is not initiated within 24 hours of symptom onset 3
- Do not use topical antivirals as primary therapy: Systemic valacyclovir is substantially more effective than topical treatments 3
Special Populations
- Renal impairment: Dose adjustment is required for patients with significant renal dysfunction 3
- Immunocompromised patients: May require higher doses or longer treatment duration; close monitoring is indicated 1, 3
- Athletes with frequent recurrences: Consider suppressive therapy rather than episodic treatment 3