Are sedating antihistamines (antihistamines that cause drowsiness) safe for use during breastfeeding?

Sedating Antihistamines and Breastfeeding Safety

Sedating antihistamines should generally be avoided during breastfeeding when possible, as they can cause drowsiness in infants and potentially affect milk supply. 1, 2

Safety Profile of Antihistamines During Breastfeeding

First-Generation (Sedating) Antihistamines

• Diphenhydramine (Benadryl): FDA labeling specifically warns to consult a healthcare professional before use while breastfeeding 1
• Diazepam: Known to be transferred in breast milk in significant levels; should only be considered as a one-off dose before procedures 2
• Potential risks to infant:
  • Drowsiness
  • Poor feeding
  • Decreased alertness
  • Respiratory depression in severe cases

Second-Generation (Non-Sedating) Antihistamines

• Generally considered safer for breastfeeding mothers 3
• Preferred over first-generation antihistamines due to fewer side effects 3
• Minimal transfer into breast milk with minimal effects on infants 4

Clinical Decision-Making Algorithm

1. First-line approach: Use non-sedating second-generation antihistamines when antihistamine therapy is required during breastfeeding

   • Examples: loratadine, cetirizine, fexofenadine 5

2. If sedating antihistamine is absolutely necessary:

   • Use the lowest effective dose for the shortest duration possible
   • Time administration:
     • Take immediately after breastfeeding
     • Allow maximum time before next feeding (4-6 hours when possible)
   • Monitor infant for signs of:
     • Unusual drowsiness
     • Poor feeding
     • Respiratory changes
     • Decreased alertness 2

3. High-risk situations requiring increased vigilance:

   • Premature infants
   • Newborns (first 2 months)
   • Infants with existing medical conditions
   • Mothers taking multiple medications 6

Important Safety Considerations

• Bed-sharing precautions: Mothers taking sedating antihistamines should avoid co-sleeping with infants due to reduced alertness and responsiveness 6
• Milk supply concerns: Some sedating antihistamines may potentially decrease milk production
• Maternal functioning: Sedating antihistamines may impair the mother's ability to safely care for her infant 6

Special Circumstances

• Single-dose use: For occasional/emergency use, a single dose of a sedating antihistamine may be acceptable with proper monitoring
• Regular/chronic use: Long-term use of sedating antihistamines should be avoided during breastfeeding 2

When antihistamine treatment is necessary during breastfeeding, the benefits of treating the mother's symptoms must be weighed against potential risks to the infant, with preference given to non-sedating options whenever possible.