What is the recommended dose of acyclovir (antiviral medication) cream and oral tablets for recurrent Herpes Simplex Virus (HSV) infections?

Recommended Dosage of Acyclovir for Recurrent HSV Infections

For recurrent HSV infections, oral acyclovir should be administered at 400 mg three times daily for 3-5 days, while topical 5% acyclovir cream should be applied 5 times daily at the first sign of symptoms. 1

Oral Acyclovir Dosing for Recurrent HSV

Standard Regimens:

• Oral therapy for immunocompetent patients:
  • Acyclovir 400 mg three times daily for 3-5 days 1
  • Alternative: Acyclovir 800 mg three times daily for 2 days (shorter course option) 2

Special Populations:

• Immunocompromised patients:
  • May require longer duration of therapy
  • Consider higher doses: 800 mg five times daily 3
  • Monitor closely for disseminated disease

Dosage Adjustment for Renal Impairment:

Based on creatinine clearance 4:

• CrCl >25 mL/min: 400 mg every 12 hours or 800 mg 5 times daily
• CrCl 10-25 mL/min: 400 mg every 12 hours or 800 mg every 8 hours
• CrCl 0-10 mL/min: 200 mg every 12 hours or 800 mg every 12 hours

Topical Acyclovir for Recurrent HSV

• 5% acyclovir cream applied 5 times daily 1
• Start at the earliest sign of prodrome or lesion
• Continue until all lesions have healed
• Most effective when applied early in the course of an outbreak

Suppressive Therapy for Frequent Recurrences

For patients with frequent recurrences (≥6 episodes/year), suppressive therapy may be considered:

• Acyclovir 400 mg twice daily 5
• Alternative: Acyclovir 400 mg 2-3 times daily 1
• Continue for up to 12 months, then reassess

Treatment Considerations and Pitfalls

Key Points for Effective Treatment:

• Early initiation is crucial for maximum efficacy 6
• Complete the full course of treatment
• For topical therapy, apply at the first sign of prodrome for best results

Common Pitfalls to Avoid:

1. Delayed treatment initiation: Efficacy decreases significantly when treatment is started after lesions have fully developed
2. Inadequate dosing: Underdosing may lead to treatment failure
3. Premature discontinuation: Continue until all lesions have healed
4. Failure to adjust dose for renal impairment: Can lead to toxicity

Treatment Resistance:

• Resistance is rare in immunocompetent patients but more common in immunocompromised hosts 3
• If treatment failure occurs after 5-7 days of therapy, consider:
  • Increasing oral acyclovir to 800 mg five times daily
  • Viral culture and susceptibility testing
  • Alternative antivirals (foscarnet) for confirmed resistance 3

Comparative Efficacy

The shorter 2-day regimen (800 mg three times daily) has been shown to significantly reduce:

• Duration of lesions (4 days vs. 6 days with placebo)
• Duration of viral shedding (25 hours vs. 58.5 hours)
• Proportion of aborted episodes 2

This provides a convenient alternative for patients who prefer shorter treatment courses while maintaining efficacy.