What is the recommended treatment for cold sores?

Cold Sore Treatment Recommendations

The recommended treatment for cold sores is valacyclovir 2 grams twice daily for 1 day, initiated at the earliest symptom of a cold sore (prodrome phase - tingling, burning, itching). 1, 2

First-Line Treatment Options

Oral Antiviral Medications

• Valacyclovir (preferred): 2 grams twice daily for 1 day, taken 12 hours apart 1, 2

  • Most convenient dosing regimen
  • Reduces median healing time by approximately 1 day 3
  • Should be started at the earliest symptom (tingling, itching, or burning)
  • Higher bioavailability than acyclovir (3-5 times better absorbed) 3

• Acyclovir:

  • 400mg orally three times daily for 5-7 days OR
  • 200mg orally five times daily for 5-7 days 1, 4
  • Particularly recommended during pregnancy due to established safety profile 1

• Famciclovir:

  • Single dose of 1500mg 1
  • Reduces median time to healing by 1.8 days compared to placebo
  • Common side effects: headache (<10%), nausea (<4%) 1

Treatment for Special Populations

Immunocompromised Patients

• Higher doses and longer treatment duration required:
  • Acyclovir 400mg five times daily for 7-10 days 1
  • For severe cases: Acyclovir 5-10 mg/kg IV three times daily until lesions begin to regress, then switch to oral therapy 4

Patients with Frequent Recurrences (≥6 episodes/year)

• Consider suppressive therapy:
  • Acyclovir 400mg twice daily OR
  • Valacyclovir 500-2000mg daily 1

Acyclovir-Resistant Infections

• Foscarnet: 40 mg/kg IV three times daily or 60 mg/kg IV twice daily 4, 1
• Resistance to antivirals remains low (<0.5%) in immunocompetent patients 1

Important Clinical Considerations

1. Timing is critical:

   • Treatment should be initiated at the earliest symptom (prodrome phase)
   • Delayed treatment (>48 hours after symptom onset) significantly decreases efficacy 1

2. Patient expectations:

   • Antivirals decrease episode duration by approximately one day but don't completely abort lesions 1
   • Treatment is most effective when started during the prodrome phase 2

3. Prevention strategies:

   • Avoid known triggers: UV radiation (use sunscreen SPF 15+), fever, psychological stress, local trauma 1
   • Keep the area clean and dry to prevent secondary infection 1
   • For UV-induced cold sores, sunscreen application can be preventive 5

4. Treatment failure:

   • If lesions do not begin to resolve within 7-10 days, consider treatment failure and possible resistance 1
   • Alternative treatments for resistant cases include topical trifluridine or intravenous foscarnet 1, 6

Remember that cold sores are highly contagious, and patients should be advised to avoid close contact with others during active outbreaks to prevent transmission 7.