Recommended Valacyclovir Dosing for HSV-2 in HIV Patients
For HIV-infected patients with HSV-2 infection, the recommended dose of valacyclovir (Valtrex) is 500 mg twice daily for suppressive therapy. 1, 2
Dosing Recommendations Based on Clinical Scenario
Suppressive Therapy
- For HIV-infected patients with CD4+ count ≥100 cells/mm³, valacyclovir 500 mg twice daily is recommended for chronic suppressive therapy of recurrent genital herpes 1, 2, 3
- This higher dosing (compared to immunocompetent patients) is recommended due to potentially more severe and frequent recurrences in immunocompromised patients 2
- Valacyclovir 1000 mg once daily is not recommended for HIV patients, as studies have shown it to be inferior to the 500 mg twice daily regimen 4
Episodic Treatment
- For treatment of recurrent episodes in HIV patients, valacyclovir 1000 mg twice daily is recommended 1, 4
- Treatment should be continued until lesions have completely healed 1
- Short-course therapy (1-3 days) should not be used in patients with HIV infection 1
Clinical Evidence
- Clinical trials have demonstrated that valacyclovir 500 mg twice daily is as effective as acyclovir 400 mg twice daily for HSV suppression in HIV-infected individuals 4
- Valacyclovir provides better oral bioavailability than acyclovir, allowing for less frequent dosing while maintaining efficacy 5
- Daily suppressive therapy with valacyclovir in HIV-infected persons results in a decrease in HIV concentration in plasma and genital secretions, though the clinical benefit of this effect remains uncertain 1, 6
Monitoring and Safety Considerations
- No laboratory monitoring is needed in patients receiving suppressive therapy unless they have substantial renal impairment 1, 2
- Valacyclovir is generally well tolerated at dosages used for suppression of recurrent genital herpes (500 to 1000 mg/day) in HIV-seropositive individuals 5
- Common side effects include headache, nausea, and occasionally gastrointestinal complaints 5
- 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, 2, 5
Treatment Failure Considerations
- If lesions do not begin to resolve within 7-10 days after initiation of therapy, treatment failure due to resistance should be suspected 1
- For suspected acyclovir-resistant HSV, viral culture of the lesion should be obtained and susceptibility testing performed 1
- All acyclovir-resistant strains are also resistant to valacyclovir 2
- The treatment of choice for acyclovir-resistant HSV is IV foscarnet 1, 2
Duration of Therapy
- Suppressive therapy can be continued long-term, with safety and efficacy documented for up to 6 years with acyclovir and 1 year with valacyclovir 2
- After 1 year of continuous suppressive therapy, consider discussing discontinuation to assess recurrence frequency, as recurrences may decrease over time in some patients 2
Remember that while suppressive therapy significantly reduces the frequency of recurrences, it does not eliminate asymptomatic viral shedding completely 2.