Valtrex (Valacyclovir) Dosing for Cold Sores
The recommended dosage of Valtrex (valacyclovir) for treatment of cold sores (herpes labialis) is 2 grams twice daily for 1 day, taken 12 hours apart. 1
Timing of Treatment
Treatment should be initiated at the earliest symptom of a cold sore, such as:
- Tingling
- Itching
- Burning
Early initiation of therapy is critical for maximum effectiveness. Starting treatment during the prodromal phase (before visible lesions appear) provides the best outcomes.
Evidence Supporting This Regimen
The FDA-approved dosing regimen is supported by high-quality clinical evidence. Two randomized, double-blind, placebo-controlled studies demonstrated that the 1-day valacyclovir treatment regimen (2g twice daily for 1 day) was effective in:
- Reducing the median duration of cold sore episodes by approximately 1 day (p=0.001) 2
- Decreasing the time to lesion healing 2
- Reducing the time to cessation of pain and discomfort 2
- Potentially preventing lesion development in some patients 2
Advantages Over Other Regimens
The 1-day valacyclovir regimen offers several advantages:
- Convenient dosing (only two doses required)
- Better compliance compared to 5-times daily acyclovir regimens
- Superior bioavailability compared to oral acyclovir (3-5 times higher) 2
- Equivalent efficacy to longer treatment courses 3
Safety Considerations
Valacyclovir is generally well-tolerated for cold sore treatment. In clinical studies, the adverse event profile was similar between valacyclovir and placebo groups, with headache being the most commonly reported side effect 3.
Dosage Adjustments for Special Populations
Renal Impairment
For patients with reduced renal function, dosage adjustments are necessary:
- Creatinine clearance 30-49 mL/min: No reduction needed
- Creatinine clearance 10-29 mL/min: 1 gram every 24 hours
- Creatinine clearance <10 mL/min: 500 mg every 24 hours 1
Hemodialysis Patients
Patients requiring hemodialysis should receive the recommended dose after hemodialysis 1.
Practical Considerations
- Valacyclovir may be taken without regard to meals 1
- For maximum effectiveness, patients should keep the medication readily available to begin treatment at the first sign of a cold sore
- The complete treatment consists of just two doses taken in a single day, which enhances compliance
Alternative Treatments
While valacyclovir is highly effective for cold sores, alternative antiviral options include:
However, the convenience of the valacyclovir regimen (just two doses in one day) makes it a preferred option for many patients with cold sores.