Valacyclovir Dosage for Herpes Labialis
For episodic treatment of herpes labialis (cold sores), the recommended dosage is valacyclovir 2 grams twice daily for 1 day, with doses taken 12 hours apart. 1, 2
Episodic Treatment Regimen
The standard dose is 2 grams taken twice in a single day, separated by 12 hours - this high-dose, short-duration regimen is FDA-approved and recommended by the American Academy of Dermatology 1, 2
Treatment must be initiated at the earliest symptom (tingling, itching, or burning) during the prodromal phase or within 24 hours of lesion onset for optimal efficacy 3, 1
This 1-day regimen reduces the median duration of cold sore episodes by approximately 1.0 day compared to placebo (4.0-5.0 days vs 5.0 days, p<0.001) 3, 4
The regimen accelerates healing time, decreases pain, and may potentially prevent lesion development when started during prodrome 3, 1
Suppressive Therapy for Frequent Recurrences
For patients with 6 or more recurrences per year, consider chronic suppressive therapy with valacyclovir 500 mg once daily 5
The dose can be increased to 1000 mg once daily for very frequent recurrences 5
Daily suppressive therapy reduces recurrence frequency by ≥75% and significantly prolongs time to first recurrence 5, 6
After 1 year of continuous suppressive therapy, consider discontinuation to reassess recurrence rate, as frequency naturally decreases over time in many patients 5
Dosage Adjustments for Renal Impairment
For cold sores with creatinine clearance 30-49 mL/min: 1 gram every 12 hours for 1 day (do not exceed 1 day of treatment) 2
For creatinine clearance 10-29 mL/min: 1 gram every 24 hours 2
For creatinine clearance <10 mL/min: 500 mg every 24 hours 2
Patients on hemodialysis should receive the recommended dose after dialysis 2
Special Populations
Pediatric patients ≥12 years: Same adult dosing (2 grams twice daily for 1 day) 2
Immunocompromised patients: Standard dosing is typically used, but these patients should be monitored more closely as they may experience longer, more severe episodes and have higher resistance rates (7% vs <0.5% in immunocompetent patients) 1, 5
Critical Timing Considerations
Peak viral titers occur within the first 24 hours after lesion onset, making early intervention essential 5
Efficacy decreases significantly when treatment is initiated after lesions have fully developed 5
Patient-initiated therapy at first symptoms may prevent lesion development in some cases 5
Safety Profile
Valacyclovir is generally well-tolerated with minimal adverse events 3, 1
Common side effects include headache (<10%), nausea (<4%), and diarrhea, which are typically mild to moderate 3, 5
No serious adverse events have been reported in clinical studies 1
Resistance to valacyclovir remains low (<0.5%) in immunocompetent hosts 3, 5
Common Pitfalls to Avoid
Starting treatment too late after lesions have fully developed significantly reduces efficacy 5
Relying solely on topical treatments when oral therapy is substantially more effective 5
Failing to consider suppressive therapy in patients with ≥6 recurrences per year who could significantly benefit 5
Not counseling patients to identify and avoid personal triggers (UV light exposure, stress, fever, menstruation) 5