What is the appropriate dosage and duration of Acyclovir (Zovirax) for treating herpes?

Acyclovir 400mg TID for 30 Days: Inappropriate Duration for Most Herpes Indications

The prescribed regimen of acyclovir 400mg three times daily for 30 days is excessive and not supported by current guidelines for any standard herpes indication. The appropriate duration depends on the specific type of herpes infection being treated, but standard treatment courses range from 5-10 days for acute episodes, not 30 days 1, 2, 3.

Correct Dosing Based on Clinical Indication

For Recurrent Genital or Oral Herpes (Most Common Indication)

• Acyclovir 400mg orally three times daily should be given for 5 days only, not 30 days 1, 2, 3
• Treatment must be initiated during prodrome or within 2 days of lesion onset for maximum benefit 2, 4
• Alternative equivalent regimens include acyclovir 200mg five times daily for 5 days or 800mg twice daily for 5 days 1, 2, 4

For First Episode Genital Herpes

• The CDC recommends acyclovir 200mg orally five times daily for 7-10 days until clinical resolution 1, 4
• Alternatively, 400mg five times daily for 10 days can be used 5
• Not 400mg three times daily for 30 days

For Chronic Suppressive Therapy (If Frequent Recurrences)

• If the intent is suppression, the correct dose is 400mg twice daily (not three times daily) 1, 4, 3
• This regimen reduces recurrence frequency by at least 75% in patients with six or more recurrences per year 1, 6
• Suppressive therapy should be reassessed after 1 year to determine ongoing need 1, 3
• Research demonstrates that 400mg twice daily is significantly more effective than lower doses for long-term suppression 7, 6

For Herpes Zoster (Shingles)

• The correct dose is 800mg five times daily for 7-10 days 3, 8
• Not 400mg three times daily

Critical Pitfalls with the Prescribed Regimen

The 30-day duration at 400mg TID represents either:

1. Incorrect dosing frequency for suppressive therapy (should be 400mg twice daily, not three times daily) 1, 3
2. Excessive duration for episodic treatment (should be 5 days for recurrent episodes or 7-10 days for first episodes) 1, 2, 4
3. Potential confusion between episodic and suppressive regimens

Recommended Action

Clarify the clinical indication immediately:

• For acute outbreak treatment: Change to 400mg TID for 5 days only 1, 2, 3
• For suppressive therapy: Change to 400mg twice daily and reassess need after 1 year 1, 3, 6
• For first episode: Consider 200mg five times daily for 7-10 days instead 1, 4

Important Counseling Points

• Acyclovir does not eradicate latent virus or prevent future recurrences after discontinuation 2, 5
• Patients should abstain from sexual activity or close contact while lesions are present 1, 4
• Viral transmission can occur during asymptomatic periods despite treatment 1, 2
• Most immunocompetent patients with recurrent disease experience limited benefit if treatment is not started early 1, 2