There is a paucity of studies regarding the safety of cyclosporin in breast feeding mothers. Cyclosporin passes into breast milk, and concentrations in breast milk have been shown to be variable, ranging from 16 microg/L to 596 microg/L.1-4 Effects on foetus and infant have been studied but to date no significant adverse effects have been attributed to the drug at any concentration.5-6
This case report aims to focus on assessing trends of cyclosporin testing in breast milk, encouraging further study into cyclosporin effects in mothers wishing to breastfeed and highlighting the difficulties clinicians have in counselling these patients.
We present a case report of a patient wanting to breast feed whilst on cyclosporin therapy. Following literature review, she was counselled not to breastfeed her preterm 28-week-old infant owing to a lack of evidence of drug safety for cyclosporin use in lactating mothers.
The patient was commenced on intravenous cyclosporin infusion followed by twice daily tablet dosing for a flare of severe newly diagnosed biopsy-proven ulcerative colitis that was non-responsive to steroids.
Levels of cyclosporin in breast milk and maternal serum were tested in the immediate postpartum period whilst on cyclosporin IV infusion and subsequently with oral cyclosporin therapy.
The levels of cyclosporin measured in breast milk in this patient ranged from <5 microg/L to 274 microg/L. Cyclosporin levels in breast milk are variable and appear to approach a steady state after 24 hours of intravenous drug commencement.
Whilst there is limited data, maximum cyclosporin levels in breast milk are lower than prior published literature and there appeared to be no significant difference in breast milk levels according to timing of dosage of oral cyclosporin at 7 days post commencement.
Further research and discussion around cyclosporin in breastfeeding is required in order to counsel mothers taking the drug.