Also known as Claritin, Loratadina, Loratadinum

A piperidine histamine H1-receptor antagonist with anti-allergic properties and without sedative effects. Loratadine blocks the H1 histamine receptor and prevents the symptoms that are caused by histamine activity on capillaries, bronchial smooth muscle, and gastrointestinal smooth muscle, including vasodilatation, increased capillary permeability, bronchoconstriction, and spasmodic contraction of gastrointestinal smooth muscle. Loratadine does not cross the blood-brain barrier and does not cause central nervous system effects.

Originator: NCI Thesaurus | Source: The website of the National Cancer Institute (http://www.cancer.gov)

Can I take Loratadine while breastfeeding?

Because of its lack of sedation and low milk levels, maternal use of loratadine would not be expected to cause any adverse effects in breastfed infants. Loratadine might have a negative effect on lactation, especially in combination with a sympathomimetic agent such as pseudoephedrine. The British Society for Allergy and Clinical Immunology recommends loratadine at its lowest dose as a preferred choice if an antihistamine is required during breastfeeding.[1]

Drug levels

After a single oral dose of 40 mg of loratadine in 6 women, average peak milk levels of 29.2 (range 20.4 to 39) mcg/L occurred at two hours after the dose. In addition, average desloratadine peak milk levels of 16 (range 9 to 29.6) mcg/L occurred at 5.3 hours after the dose. The total amount excreted in milk over 48 hours was 11.7 mcg of loratadine and its metabolite. However, the dose administered was four times greater than the usual dose of the drug, so a total dose of about 3 mcg would be expected with a 10 mg dose. The calculated average and maximum expected doses of loratadine plus desloratadine in milk were 0.46 and 1.1% and of the maternal weight-adjusted dose, respectively, after the 40 mg dose.[2]

Effects in breastfed infants

After a single oral dose of 40 mg of loratadine in 6 women, average peak milk levels of 29.2 (range 20.4 to 39) mcg/L occurred at two hours after the dose. In addition, average desloratadine peak milk levels of 16 (range 9 to 29.6) mcg/L occurred at 5.3 hours after the dose. The total amount excreted in milk over 48 hours was 11.7 mcg of loratadine and its metabolite. However, the dose administered was four times greater than the usual dose of the drug, so a total dose of about 3 mcg would be expected with a 10 mg dose. The calculated average and maximum expected doses of loratadine plus desloratadine in milk were 0.46 and 1.1% and of the maternal weight-adjusted dose, respectively, after the 40 mg dose.[2]

Possible effects on lactation

Antihistamines in relatively high doses given by injection can decrease basal serum prolactin in nonlactating women and in early postpartum women.[5][6] However, suckling-induced prolactin secretion is not affected by antihistamine pretreatment of postpartum mothers.[5] 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. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

One mother out of 51 mothers who took loratadine while nursing reported that she had decreased milk production after taking loratadine 10 mg daily for less than one week at 4 months postpartum.[3]

Alternate drugs to consider

Desloratadine, Fexofenadine

References

1. Powell RJ, Du Toit GL, Siddique N et al. BSACI guidelines for the management of chronic urticaria and angio-oedema. Clin Exp Allergy. 2007;37:631-50. PMID: 17456211

2. Hilbert J, Radwanski E, Affine MB et al. Excretion of loratadine in human breast milk. J Clin Pharmacol. 1988;28:234-9. PMID: 2966185

3. Messinis IE, Souvatzoglou A, Fais N et al. Histamine H1 receptor participation in the control of prolactin secretion in postpartum. J Endocrinol Invest. 1985;8:143-6. PMID: 3928731

4. Merlob P, Stahl B. Prospective follow-up of adverse reactions in breast-fed infants exposed to loratadine treatment (1999-2001). BELTIS Newsl. 2002;Number 10:43-51.

5. Merlob P. Prospective follow-up of adverse reactions in breast-fed infants exposed to maternal loratadine treatment (1999-2002). Unpublished manuscript.

6. Pontiroli AE, De Castro e Silva E, Mazzoleni F et al. The effect of histamine and H1 and H2 receptors on prolactin and luteinizing hormone release in humans: sex differences and the role of stress. J Clin Endocrinol Metab. 1981;52:924-8. PMID: 7228996

Last Revision Date

20131022

Disclaimer:Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.

Source: LactMed – National Library of Medicine (NLM)

3D Model of the Loratadine molecule

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