Is Zykast (levocetirizine) safe to use during breastfeeding in a healthy postpartum woman?

Zykast (Levocetirizine) Safety During Breastfeeding

Zykast (levocetirizine) should be used with caution during breastfeeding, as the FDA drug label for cetirizine (the parent compound) states it is "not recommended" for breastfeeding mothers. 1

Evidence-Based Recommendation

Primary Safety Concern

• The FDA drug label for cetirizine explicitly advises that breastfeeding is "not recommended" when taking this medication 1
• Levocetirizine is the active R-enantiomer of cetirizine, and while specific breastfeeding data for levocetirizine is limited, the FDA's conservative stance on cetirizine should guide clinical decision-making 1

Clinical Decision Algorithm

If antihistamine treatment is necessary during breastfeeding:

1. First-line approach: Consider alternative medications with better-established safety profiles during lactation 2

   • Inhaled and nasal treatments for allergic rhinitis are unlikely to affect breastfed infants and represent safer alternatives 2

2. If oral antihistamine is specifically required:

   • Consult current resources such as LactMed (NIH database) for the most up-to-date safety information on levocetirizine specifically 2
   • Assess the risk-benefit ratio: the severity of maternal symptoms versus potential infant exposure 3

3. If Zykast must be used:

   • Use the lowest effective dose 2
   • Time dosing before the infant's longest sleep interval to minimize infant exposure 2
   • Monitor the breastfed infant for sedation or other adverse effects 2

Important Caveats

• Most commonly used drugs are relatively safe for breastfed babies, with the dose received via milk generally being small 4
• Few drugs are absolutely contraindicated during breastfeeding (anticancer drugs, lithium, oral retinoids, iodine, amiodarone, and gold salts) 4
• The fundamental principle is risk-benefit assessment: prioritize treating the mother effectively while minimizing infant risk 3
• Excessive caution may lead to unnecessary breastfeeding interruption without proper evidence assessment 5

Common Pitfall to Avoid

• Do not automatically discontinue breastfeeding based solely on product labeling without consulting specialized lactation resources, as pharmaceutical manufacturers often provide overly conservative recommendations due to lack of specific studies rather than evidence of harm 5