What is the recommended dosage and treatment regimen for herpes simplex virus infections with Zovirax (acyclovir) cream?

Zovirax Cream Dosage and Treatment

Zovirax (acyclovir) cream is NOT recommended for treatment of herpes simplex virus infections, as topical acyclovir is substantially less effective than oral formulations and its use is discouraged. 1

Why Topical Acyclovir Should Be Avoided

• Topical acyclovir therapy is substantially less effective than oral acyclovir and the CDC explicitly discourages its use for genital herpes and other HSV infections 1
• While topical acyclovir may speed healing in immunocompromised patients with chronic ulcerative herpetic lesions, it should only be used when adding another systemic drug is undesirable 2
• The evidence for efficacy of topical acyclovir cream in recurrent episodes has been equivocal 3

Recommended Treatment Instead: Oral Acyclovir

For First Clinical Episode of Genital Herpes

• Acyclovir 200 mg orally 5 times daily for 7-10 days or until clinical resolution 1
• For first-episode herpes proctitis: Acyclovir 400 mg orally 5 times daily for 10 days 1

For Recurrent Episodes

• Acyclovir 400 mg orally 3 times daily for 5 days is the standard episodic treatment for adults and adolescents 4
• Alternative regimens include:
  • Acyclovir 200 mg orally 5 times daily for 5 days 1
  • Acyclovir 800 mg orally 2 times daily for 5 days 1
• Treatment should be initiated during prodrome or within 2 days of lesion onset for maximum benefit 1

For Daily Suppressive Therapy (≥6 recurrences per year)

• Acyclovir 400 mg orally twice daily is the CDC-recommended standard suppressive regimen 1, 4
• This reduces recurrence frequency by at least 75% 1
• Alternative: Acyclovir 200 mg orally 3-5 times daily to identify the lowest effective dose 1
• Reassess after 12 months of continuous therapy 4

For Pediatric Patients (<45 kg)

• Acyclovir 20 mg/kg body weight (maximum 400 mg/dose) orally 3 times daily for 5-10 days 1, 4

For Severe Disease Requiring Hospitalization

• Acyclovir 5-10 mg/kg IV every 8 hours for 5-7 days or until clinical resolution 1
• For CNS or disseminated disease: Acyclovir 10 mg/kg IV 3 times daily for 21 days 1, 4

Important Clinical Pitfalls

• Do not use short-course therapy (1-3 days) in immunocompromised patients 4
• Topical therapy should not be applied to the eyes; ocular involvement requires systemic therapy 1
• Most immunocompetent patients with recurrent disease do not benefit significantly from episodic treatment, making suppressive therapy the preferred approach for frequent recurrences 1
• Acyclovir-resistant strains may develop, particularly in immunocompromised patients receiving prolonged therapy, requiring alternative agents like foscarnet 1, 5