What is the recommended dose of valacyclovir (Valtrex) for the treatment of oral herpes?

Valacyclovir Dosing for Oral Herpes (Herpes Labialis)

For oral herpes (cold sores), the recommended dose of valacyclovir is 2 grams twice daily for 1 day, with doses taken 12 hours apart, initiated at the earliest sign of symptoms such as tingling, itching, or burning. 1, 2

Standard Treatment Regimen

• The FDA-approved dosing is valacyclovir 2 grams twice daily for 1 day (total of 4 grams over 12 hours) for adults and adolescents ≥12 years of age 2
• Treatment must be initiated at the earliest symptom of a cold sore—during the prodromal phase when tingling, itching, or burning first occurs—for maximum benefit 1, 2
• This single-day, high-dose regimen is endorsed by the American Academy of Dermatology as optimal for efficacy 1

Clinical Efficacy

• The 1-day valacyclovir regimen significantly reduces median episode duration to 4.0-5.0 days compared to 5.0 days with placebo (p<0.001) 3, 1
• This short-course therapy can reduce symptom duration, decrease pain, accelerate healing time, and may potentially prevent lesion development when started during prodrome 1
• The high strength of evidence supports this regimen's effectiveness in reducing morbidity and improving quality of life 1

Administration Details

• Valacyclovir may be given without regard to meals 2
• The two 2-gram doses should be separated by exactly 12 hours 2
• For pediatric patients <12 years or those unable to swallow tablets, an oral suspension (25 mg/mL or 50 mg/mL) can be prepared extemporaneously from 500-mg tablets 2

Alternative Antiviral Options

If valacyclovir is unavailable or contraindicated, alternative regimens include:

• Famciclovir 1500 mg as a single dose, which reduces median healing time to 4.4 days versus 6.2 days with placebo (p<0.001) 3, 4
• Acyclovir 800 mg twice daily for 5 days, though this requires a longer treatment course and less convenient dosing 5

Critical Timing Consideration

• Early initiation is the single most important factor for efficacy—treatment started during prodrome or within the first hours of lesion appearance provides maximum benefit 4
• Starting therapy after the lesion is fully developed significantly reduces effectiveness 5

Safety Profile

• Valacyclovir is generally well-tolerated for oral herpes treatment 1
• Common adverse events include headache, nausea, and gastrointestinal complaints, with no serious adverse events reported in studies of immunocompetent patients 1
• The drug neither eradicates latent virus nor affects subsequent recurrence risk, frequency, or severity 5

Special Populations

• Immunocompromised patients: Standard dosing is typically used, but closer monitoring is warranted 1
• HIV-infected patients: For recurrent orolabial herpes, extended regimens rather than single-dose therapy may be required 4
• Renal impairment: Dose adjustment is not specifically addressed in FDA labeling for the 1-day oral herpes regimen, but caution is warranted in severe renal dysfunction 2

Common Pitfalls to Avoid

• Do not delay treatment waiting for full lesion development—the prodromal phase is the optimal treatment window 1, 4
• Do not confuse the oral herpes dosing (2 grams twice daily for 1 day) with genital herpes dosing (different regimens) 2
• Do not use the high-dose regimen (8 g/day) studied for CMV prophylaxis, as this has been associated with serious adverse events including thrombotic microangiopathy in immunocompromised patients 6