What is the recommended treatment for a cold sore in a patient 30 weeks pregnant?

Treatment of Cold Sores During Pregnancy (30 Weeks)

Oral acyclovir 200mg five times daily for 5-7 days is the recommended first-line treatment for cold sores in pregnant women at 30 weeks gestation. 1

First-Line Treatment Options

Oral Antiviral Therapy

• Acyclovir (preferred): 200mg 5 times daily for 5-7 days
  • Start within 72 hours of symptom onset (ideally within 24-48 hours)
  • Extensive safety data in pregnancy with no increased risk of birth defects 1
  • Significantly reduces symptom duration (8.1 days vs 12.5 days) and pain duration (2.5 days vs 3.9 days) compared to placebo 1

Alternative Oral Antivirals (if acyclovir unavailable)

• Valacyclovir: 1g twice daily for 7 days
  • Limited but generally reassuring safety data in pregnancy 1
  • Better bioavailability than acyclovir but less pregnancy safety data
• Famciclovir: Not recommended due to insufficient safety data in pregnancy 1

Topical Treatment Options

• Topical acyclovir: Can be used as an adjunct to oral therapy

  • Less effective than oral therapy when used alone
  • Apply 5 times daily for 5-7 days

• Penciclovir (Denavir): FDA label states "Before you use Denavir, tell your doctor if you are pregnant" but doesn't specifically contraindicate use in pregnancy 2

  • Apply every 2 hours during waking hours for 4 days
  • Start at earliest sign of cold sore

Supportive Measures

• Pain management: Acetaminophen is the safest analgesic during pregnancy 3

  • Use lowest effective dose for shortest duration
  • Avoid NSAIDs in third trimester due to risk of premature closure of fetal ductus arteriosus 4, 5

• Hydration and nutrition: Ensure adequate fluid intake and soft, non-acidic foods if oral pain is significant

Special Considerations for Pregnancy at 30 Weeks

1. Timing considerations: At 30 weeks gestation, the risk of preterm birth from untreated infection may outweigh theoretical medication risks

2. Monitoring: If lesions do not begin to resolve within 7-10 days, consider:

   • Treatment failure
   • Possible resistance
   • Secondary bacterial infection 1

3. Prevention of recurrence: Consider suppressive therapy with acyclovir 400mg twice daily if:

   • Multiple recurrences during pregnancy
   • Approaching delivery (typically started at 36 weeks) 1, 6

Important Precautions

• Avoid topical steroids unless specifically prescribed, as they may worsen infection
• Wash hands thoroughly before and after applying any medication
• Avoid touching or picking at lesions to prevent spreading infection
• Inform obstetrician about the cold sore, especially if delivery is imminent

Follow-up Recommendations

• Follow up if lesions worsen or don't improve within 7 days
• Consider suppressive therapy if this is a recurrent episode
• Discuss prevention strategies to avoid triggers (UV radiation, stress, local trauma) 1

Oral acyclovir is the most extensively studied antiviral in pregnancy and provides the best balance of efficacy and safety for treating cold sores at 30 weeks gestation. Starting treatment promptly is key to reducing duration and severity of symptoms.