What is the recommended valacyclovir (Valtrex) dosing regimen for an adult with a recurrent genital herpes outbreak and normal renal function?

Valacyclovir Dosing for Recurrent Genital Herpes Episodes

For an adult with normal renal function experiencing a recurrent genital herpes outbreak, take valacyclovir 500 mg twice daily for 3 days, initiated at the first sign or symptom of the episode. 1

Episodic Treatment Regimen

• The FDA-approved dosing is 500 mg twice daily for 3 days for treatment of recurrent genital herpes episodes 1
• Therapy must be initiated at the very first sign or symptom of an outbreak (tingling, itching, burning, or visible lesion) to maximize effectiveness 1
• The CDC supports this 3-day regimen as well as an alternative 5-day course (500 mg twice daily for 5 days) 2

Alternative Dosing Options

• Valacyclovir 1000 mg once daily for 5 days is equally effective as the 500 mg twice-daily regimen, offering a simpler once-daily option if preferred 3
• Both regimens demonstrate equivalent efficacy in healing lesions, reducing pain/discomfort, and achieving abortive episodes 3

Critical Timing Consideration

• Early patient-initiated therapy significantly increases the chance of aborting the outbreak before vesicular or ulcerative lesions fully develop 4
• Treatment is most effective when started within 48 hours of symptom onset, though earlier is always better 1

When to Consider Suppressive Therapy Instead

If your patient experiences frequent recurrences, episodic treatment may not be the optimal strategy:

• Patients with ≥6 recurrences per year should be offered daily suppressive therapy rather than episodic treatment 5
• For patients with <10 recurrences annually, suppressive dosing is 500 mg once daily 2, 1
• For patients with ≥10 recurrences per year, increase suppressive dosing to 1000 mg once daily, as 500 mg daily is less effective in this high-frequency population 2, 6
• Suppressive therapy reduces recurrence frequency by ≥75% 2, 6

Special Population: HIV-Infected Patients

• HIV-infected patients should NOT use the 3-day short-course regimen 6
• HIV-positive patients with CD4+ count ≥100 cells/mm³ require 5-14 days of treatment for acute episodes (not 3 days) 6
• For suppressive therapy in HIV patients, use 500 mg twice daily (not once daily) 2, 5, 6

Common Pitfall to Avoid

• Do not prescribe the 1-day cold sore regimen (2 grams twice daily for 1 day) for genital herpes—this dosing is FDA-approved only for herpes labialis, not genital herpes 1

Treatment Failure

• If lesions do not begin to resolve within 7-10 days of appropriate therapy, suspect acyclovir resistance 5, 6
• Obtain viral culture with susceptibility testing to confirm resistance 5, 6
• All acyclovir-resistant strains are also resistant to valacyclovir 2, 6
• IV foscarnet is the treatment of choice for confirmed resistant HSV 2, 5, 6

Safety and Monitoring

• Valacyclovir may be given without regard to meals 1
• No laboratory monitoring is needed unless the patient has substantial renal impairment 2, 6
• Common adverse effects include headache and nausea, which are generally mild 6
• Dose adjustment is NOT required for creatinine clearance ≥30 mL/min 2