What is the treatment for herpes (Herpes Simplex Virus) on the lips, also known as cold sores?

Treatment of Herpes Simplex Virus on Lips (Cold Sores)

Oral valacyclovir 2g twice daily for 1 day is the first-line treatment for cold sores on the lips, providing the most effective reduction in duration and symptoms when initiated early. 1, 2, 3

First-Line Treatment Options

• Valacyclovir 2g twice daily for 1 day is the most effective treatment, reducing median episode duration by approximately 1 day compared to placebo, with treatment ideally initiated during the prodromal stage (tingling, itching, burning) 1, 3, 4
• Famciclovir 1500mg as a single dose is an effective alternative, significantly reducing healing time of primary lesions 1, 2
• Acyclovir 400mg five times daily for 5 days is another option but requires more frequent dosing 2, 5

Treatment Timing and Efficacy

• Treatment must be initiated within 24 hours of symptom onset for maximum effectiveness, ideally during the prodromal stage 1, 2, 3
• The FDA specifically notes that valacyclovir efficacy has not been established when initiated after the development of clinical signs (papule, vesicle, or ulcer) 3
• Peak viral titers occur in the first 24 hours after lesion onset, making early intervention critical to block viral replication 6, 7
• Short-course, high-dose regimens offer greater convenience, cost benefits, and may improve patient adherence 1, 2

Management of Frequent Recurrences

• Consider suppressive therapy for patients experiencing six or more recurrences per year 1, 7, 5
• Recommended suppressive therapy options include:
  • Valacyclovir 500mg once daily (can increase to 1000mg once daily for very frequent recurrences) 1, 7
  • Famciclovir 250mg twice daily 1
  • Acyclovir 400mg twice daily 1, 7
• Daily suppressive therapy reduces the frequency of herpes recurrences by ≥75% among patients with frequent recurrences 1, 7
• Topical antivirals are not effective for suppressive therapy as they cannot reach the site of viral reactivation 1, 7

Topical Treatment Options

• Topical antivirals provide only modest clinical benefit and are less effective than oral therapy 1, 8
• Options include:
  • 5% acyclovir cream/ointment (with or without hydrocortisone) 5
  • 1% penciclovir cream 5
• Topical treatments are not recommended as first-line therapy due to their limited efficacy compared to oral agents 1, 5

Prevention Strategies

• Application of sunscreen can help prevent recurrent HSL induced by ultraviolet light exposure 9
• Identify and avoid personal triggers (stress, fever, sunlight) 7
• For individuals with frequent recurrences, application of sunscreen or zinc oxide may decrease the probability of recurrent outbreaks 6

Common Pitfalls to Avoid

• Relying solely on topical treatments when oral therapy is more effective 1, 2
• Starting treatment too late, as efficacy decreases significantly when treatment is initiated after lesions have fully developed 1, 7
• Using topical antivirals for suppressive therapy, which is ineffective 1, 7
• Failing to consider suppressive therapy in patients with frequent recurrences (≥6 per year) who could significantly benefit 1, 7

Safety Considerations

• Oral antiviral medications are generally well-tolerated with minimal adverse events 1, 7
• Common side effects include headache, nausea, and diarrhea, which are typically mild to moderate 1, 7
• Despite increasing use of HSV-specific antiviral agents, the incidence of resistant HSV-1 strains remains low (<0.5% in immunocompetent hosts) 1, 7
• Adequate hydration should be maintained during treatment with oral antivirals 3