Daily Acyclovir Suppressive Therapy for HSV/VZV
Yes, acyclovir can be safely taken every night as suppressive therapy for patients with frequent or severe recurrent HSV infections, with the standard regimen being 400 mg orally twice daily (morning and evening). 1, 2
Recommended Suppressive Dosing
Daily suppressive therapy with acyclovir 400 mg orally twice daily is the CDC-recommended regimen for patients with frequent recurrences (≥6 episodes per year). 1, 2
Alternative suppressive regimens include:
- Acyclovir 200 mg orally 3-5 times daily 1
- For immunocompromised patients: 400 mg orally 3-5 times daily 3, 2
Clinical Efficacy and Outcomes
Suppressive therapy reduces recurrence frequency by at least 75% in patients with frequent episodes. 1, 2
Key clinical outcomes from long-term studies:
- 73% of patients remain completely symptom-free during continuous suppressive therapy 4
- An additional 14% experience only mild symptoms (erythema/itching) 4
- In patients treated for 3 years, 45%, 52%, and 63% remained recurrence-free in years 1,2, and 3 respectively 5
- Serial analyses showed 71-87% of patients remained recurrence-free in each 3-month quarter 5
Duration and Reassessment
After 1 year of continuous suppressive therapy, discontinue treatment to reassess the patient's recurrence rate. 1
Important considerations:
- Upon withdrawal, 69% of patients experience herpes relapse within 1-4 weeks 4
- Most patients return to their pre-treatment recurrence frequency after discontinuation 4
- Acyclovir neither eradicates latent virus nor affects long-term recurrence risk after stopping therapy 1, 6
Safety Profile
Acyclovir has an excellent safety profile with minimal adverse effects during long-term suppressive use. 7, 8
Safety data from extended use:
- No noteworthy side effects recorded during 12-month continuous therapy 4
- Allergic and adverse reactions to acyclovir are infrequent 3
- The major adverse effect is transient serum creatinine elevation during high-dose intravenous use, not relevant to oral suppressive therapy 7
- Acyclovir is well-tolerated in doses of 1-4 g/day 8
Resistance Considerations
Resistance to acyclovir is rarely encountered in immunocompetent patients receiving long-term suppressive therapy. 7
Key points about resistance:
- Acyclovir susceptibility of HSV strains does not change during suppressive treatment in immunocompetent patients 4
- Resistance can develop in immunocompromised patients, particularly those with advanced HIV infection 5
- Suspect resistance if lesions persist or do not resolve within 7-10 days of therapy 1
- Most acyclovir-resistant strains are TK-deficient mutants occurring primarily in immunocompromised hosts 5
Important Clinical Caveats
Suppressive therapy does not eliminate asymptomatic viral shedding or completely prevent transmission to sexual partners. 1
Critical counseling points:
- Patients should use latex condoms during all sexual exposures 3
- Transmission can occur during asymptomatic periods despite absence of visible lesions 1, 6
- Avoid sexual contact when herpetic lesions are evident 3
- Brief treatment interruptions (2-4 days) can lead to breakthrough episodes within days 4
Special Populations
Immunocompromised patients require higher suppressive doses: acyclovir 400 mg orally 3-5 times daily until clinical resolution. 3, 2
Additional considerations:
- HIV-infected patients may benefit from increased dosing 3
- For acyclovir-resistant HSV, foscarnet 40 mg/kg IV every 8 hours is the treatment of choice 3, 2
- Pregnancy: Current registry findings do not indicate increased risk for major birth defects, though routine suppressive use is not recommended except for patients with frequent severe recurrences 3