What is the recommended dose and duration of acyclovir (antiviral medication) for a female patient with herpes simplex?

Acyclovir Dosing for Herpes Simplex in Females

For a first episode of genital herpes simplex, treat with acyclovir 200 mg orally 5 times daily for 7-10 days until clinical resolution; for recurrent episodes, use 200 mg orally 5 times daily for 5 days (or alternative convenient regimens of 400 mg 3 times daily or 800 mg twice daily for 5 days). 1

First Clinical Episode (Primary Infection)

Initial genital herpes requires longer treatment duration:

• Acyclovir 200 mg orally 5 times daily for 7-10 days (or until clinical resolution) 1, 2
• This is the FDA-approved and CDC-recommended regimen for first episodes 1, 2
• Treatment speeds healing by 50% and stops viral shedding 90% sooner compared to no treatment 3

For severe disease requiring hospitalization (disseminated infection, encephalitis, pneumonitis, or hepatitis):

• Acyclovir 5-10 mg/kg IV every 8 hours for 5-7 days or until clinical resolution 1

Recurrent Episodes

Three equally effective dosing options for recurrent genital herpes (all for 5 days duration):

• Acyclovir 200 mg orally 5 times daily 1, 2
• Acyclovir 400 mg orally 3 times daily 1, 2
• Acyclovir 800 mg orally twice daily 1, 2

Critical timing consideration:

• Treatment must be initiated during prodrome or within 2 days of lesion onset for maximum benefit 1, 4
• Patient-initiated early treatment at first symptoms may abort episodes in some cases 5
• A 2-day course of acyclovir 800 mg three times daily has shown efficacy in reducing lesion duration (4 vs 6 days with placebo, p=0.001) and may be considered as a shorter alternative 6

Important caveat: Most immunocompetent patients with recurrent disease experience limited benefit from episodic therapy, so it is not universally recommended unless treatment can be started very early 1

Chronic Suppressive Therapy

For patients with frequent recurrences (≥6 episodes per year):

• Acyclovir 400 mg orally twice daily is the recommended suppressive regimen 1, 2
• Alternative: 200 mg orally 3-5 times daily (goal is to find lowest effective dose) 1
• Suppressive therapy reduces recurrence frequency by at least 75% 1
• Continuous suppression with 400 mg twice daily keeps 44% of patients recurrence-free for one year (vs 2% with placebo) 7

Duration and monitoring:

• Safety and efficacy documented for up to 5 years of continuous use 1
• After 1 year of suppressive therapy, discontinue to reassess the patient's recurrence rate 1, 2
• Re-evaluation after 12 months is essential as the natural history of genital herpes changes over time 2

Special Populations and Considerations

Immunocompromised patients (including HIV-infected):

• May require more aggressive therapy with prolonged treatment courses 1, 8
• Higher risk of acyclovir-resistant strains, which may require foscarnet as alternative 1, 5

Pregnancy:

• Acyclovir pharmacokinetics in late pregnancy are similar to non-pregnant adults 9
• Acyclovir 400 mg every 8 hours appears appropriate for suppression in late pregnancy, though this remains an area requiring further study 9
• Women of childbearing age should inform obstetric providers about HSV infection due to neonatal transmission risk 1

Renal impairment:

• Dose adjustment required based on creatinine clearance 2
• For CrCl 0-10 mL/min: reduce 200 mg dose to every 12 hours instead of every 4 hours 2
• Hemodialysis patients require additional dose after each dialysis session 2

Common Pitfalls to Avoid

• Do not use topical acyclovir as primary therapy - it provides no improvement in systemic symptoms and is significantly less effective than oral formulations 4, 5
• Do not expect viral eradication - acyclovir does not eliminate latent virus or affect future recurrence risk after discontinuation 4, 8
• Do not forget sexual counseling - patients should abstain from sexual activity while lesions are present, though transmission can occur during asymptomatic periods 1
• Do not continue suppressive therapy indefinitely without reassessment - yearly interruption is necessary to determine ongoing need 1, 5