Recommended Maintenance Dose of Valtrex for Herpes Simplex Virus
For suppressive therapy of recurrent genital herpes in immunocompetent patients, the recommended maintenance dose of valacyclovir (Valtrex) is 500 mg once daily, or 1000 mg once daily for patients with very frequent recurrences (≥10 episodes per year). 1, 2
Dosing Recommendations Based on Patient Population
Immunocompetent Patients
- For patients with infrequent recurrences (less than 9 per year): 500 mg once daily 1, 2
- For patients with frequent recurrences (10 or more per year): 1000 mg once daily 1, 2
- Daily suppressive therapy can reduce recurrences by ≥75% among patients with frequent episodes 1
- Safety and efficacy have been documented for up to 6 years with acyclovir and 1 year with valacyclovir 1
HIV-Infected Patients
- For HIV-infected patients with CD4+ count ≥100 cells/mm³: 500 mg twice daily 1
- Higher dosing is recommended due to potentially more severe and frequent recurrences in immunocompromised patients 1
- Daily suppressive therapy in HIV-infected persons also results in decreased HIV concentration in plasma and genital secretions 1
Clinical Considerations
Benefits of Suppressive Therapy
- Prevents or delays 85% of recurrences that would occur without treatment 3
- After 16 weeks of treatment, 69% of patients receiving valacyclovir remain recurrence-free compared to only 9.5% with placebo 3
- Suppressive therapy should be discussed with every HSV-2-infected patient 1
- Once-daily dosing provides more convenient administration than more frequent acyclovir regimens 3, 4
Monitoring and Safety
- No laboratory monitoring is needed for patients on suppressive therapy unless they have substantial renal impairment 1
- Adverse events are infrequent and generally mild, with headache being most commonly reported 5
- Dosage adjustments are necessary for patients with severe renal impairment (see table below) 2
Renal Dosage Adjustments for Suppressive Therapy
- Normal renal function (CrCl ≥50 mL/min): Standard dose
- CrCl 30-49 mL/min: No reduction needed
- CrCl 10-29 mL/min: 500 mg every 24 hours
- CrCl <10 mL/min: 500 mg every 24 hours 2
Important Considerations
- Suppressive therapy reduces but does not eliminate asymptomatic viral shedding 1
- After 1 year of continuous suppressive therapy, consider discussing discontinuation to assess recurrence frequency, as recurrences may decrease over time 1
- High-dose valacyclovir (8 g/day) has been associated with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome in immunocompromised patients, but this has not been reported at doses used for HSV suppression 1, 5
Treatment Failure
- If lesions persist despite appropriate valacyclovir treatment, consider HSV resistance 1
- All acyclovir-resistant strains are also resistant to valacyclovir 1
- For acyclovir-resistant HSV, IV foscarnet is the treatment of choice 1
Remember that while these are the standard recommended maintenance doses, individual patient factors such as frequency of outbreaks, immune status, and renal function should be considered when determining the optimal regimen.