Calcitonin and Breastfeeding

Summary of use during lactation

Little information is available on the clinical use of calcitonin during breastfeeding; however, calcitonin is a normal component of human milk where may play a role in development of enteric neurons in the breastfed infant.[1-3] Because it is a large peptide, absorption by the infant is unlikely because it is probably destroyed in the infant's gastrointestinal tract. If calcitonin is required by the mother, it is not a necessarily reason to discontinue breastfeeding calcitonin therapy is sometimes used to treat symptomatic postpartum osteoporosis, which is often treated in part by stopping lactation to reduce calcium loss.[4,5] There is no evidence that exogenous calcitonin decreases serum prolactin or lactation in nursing mothers.

Drug levels in milk and infant serum

Maternal Levels. Relevant published information was not found as of the revision date. Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

A woman with discoid lupus was taking subcutaneous calcitonin 0.5 mL every other day, azathioprine 100 mg daily, warfarin 2.5 mg every 2 days, prednisone 10 mg daily, calcitriol 0.25 mcg every 2 days, acetaminophen 650 mg twice daily, and calcium, vitamin E, and vitamin C. She was specifically evaluated for the safety of azathioprine during lactation, but continued to nurse for 12 months. Infant follow-up at 15 months of age found normal growth and development.[6]

Effects on lactation and breastmilk

Calcitonin products contain a warning that it should be avoided in nursing mothers because of animal data indicating that calcitonin can lower serum prolactin. The only human data consist of small studies performed in men and nonlactating w omen, some with normal and some with elevated serum prolactin. Several of the studies found a decrease in serum prolactin after calcitonin infusion.[7-10] Another small study found that IV infusion of human calcitonin did not lower serum prolactin in healthy volunteers who had normal serum prolactin at baseline.[11] The prolactin level in a mother with established lactation may not affect her ability to breastfeed.

References

1. Koldovský O. Hormones in milk. Vitam Horm 1995;50:77-149.7709605 PubMed
2. Bucht E, Telenius-Berg M, Lundell G, et al. Immunoextracted calcitonin in milk and plasma from totally thyroidectomized women. Evidence of monomeric calcitonin in plasma during pregnancy and lactation. Acta Endocrinol (Copenh) 1986;113:529-35.3788423 PubMed
3. Ballard O, Morrow AL. Human milk composition: Nutrients and bioactive factors. Pediatr Clin North Am 2013;60:49-74.23178060 PubMed
4. Segal E, Hochberg I, Weisman Y, et al. Severe postpartum osteoporosis with increased PTHrP during lactation in a patient after total thyroidectomy and parathyroidectomy. Osteoporos Int 2011;22:2907-11.21243337 PubMed
5. Michalakis K, Peitsidis P, Ilias I. Pregnancy- and lactation-associated osteoporosis: A narrative mini-review. Endocr Regul 2011;45:43-7.21314210 PubMed
6. Moretti ME, Verjee Z, Ito S, et al. Breast-feeding during maternal use of azathioprine. Ann Pharmacother 2006;40:2269-72.17132809 PubMed
7. Carman JS, Wyatt RJ. Reduction of serum-prolactin after subcutaneous salmon calcitonin. Lancet 1977;1:1267-8.68374
8. Isaac R, Merceron R, Caillens G, et al. Effects of calcitonin on basal and thyrotropin-releasing hormone-stimulated prolactin secretion in man. J Clin Endocrinol Metab 1980;50:1011-5.6768762 PubMed
9. Ziliotto D, Luisetto G, Heynen G, et al. Decrease in serum prolactin levels after acute intravenous injection of salmon calcitonin in normal subjects. Horm Metab Res 1981;13:64-7. doi:10.1055/s-2007-1019173 PubMed
10. Žofková I, Nedvídková J. Hypercalcaemia and calcitonin inhibit prolactin secretion. Exp Clin Endocrinol 1984;84:294-8.6441727 PubMed
11. Stevenson JC, Evans IM, Colston KW, et al. Serum-prolactin after subcutaneous human calcitonin. Lancet 1977;2:711-2.71517