Is Clemastine Fumarate Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use Clemastine Fumarate? Is Clemastine Fumarate safe for nursing mother and child? Does Clemastine Fumarate extracts into breast milk? Does Clemastine Fumarate has any long term or short term side effects on infants? Can Clemastine Fumarate influence milk supply or can Clemastine Fumarate decrease milk supply in lactating mothers?

1st generation antihistamine, ethanolamine, with moderate sedative and marked antimuscarinic effects. The latter could decrease prolactin production, which is important for milk production especially in the first few weeks. Their pharmacokinetic data (high volume of distribution and high percentage of plasma protein binding) explain the negligible excretion observed in milk (Kok 1982). However, there is a published case of a 10-week-old infant who showed signs of lethargy, irritability and rejection of feeding, although the mother took phenytoin and carbamazepine in addition to clemastine. No levels of clemastine were detected in the girl's plasma, who recovered well and continued to breastfeed (Kok 1982). Until there is more published data on this drug in relation to breastfeeding, safer known alternatives may be preferable, especially during the neonatal period and in case of prematurity. Lethargy and adequate feeding of the infant should be monitored. Co-sleeping with the baby is not recommended if this drug is being taken (UNICEF 2013, Landa 2012, ABM 2008, UNICEF 2006).

Small occasional doses of clemastine are acceptable during breastfeeding. Larger doses or more prolonged use may cause drowsiness and other effects in the infant or decrease the milk supply, particularly in combination with a sympathomimetic such as pseudoephedrine or before lactation is well established. Single bedtime doses after the last feeding of the day may be adequate for many women and will minimize any effects of the drug. The nonsedating antihistamines are preferred alternatives.

In one telephone follow-up study, mothers reported irritability and colicky symptoms 10% of infants exposed to various antihistamines and drowsiness was reported in 1.6% of infants. None of the reactions required medical attention and none of the infants were exposed to clemastine.[2] A 10-week-old breastfed infant whose mother was taking clemastine, phenytoin and carbamazepine was drowsy, refused to feed, was irritable, and had high-pitched crying.[1] These side effects were possibly caused by clemastine in breastmilk, but the other drugs could also have contributed.

Antihistamines in relatively high doses given by injection can decrease basal serum prolactin in nonlactating women and in early postpartum women.[3][4] However, suckling-induced prolactin secretion is not affected by antihistamine pretreatment of postpartum mothers.[3] Whether lower oral doses of antihistamines have the same effect on serum prolactin or whether the effects on prolactin have any consequences on breastfeeding success have not been studied.