Is Istubol Safe in Breastfeeding

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

Anti-estrogen drug with anticancer effects. May inhibit lactation. It is not safe for the mother to continue BF whenever a risk of residual tumor is likely, which actually has been the reason for using this drug. Once any risk had disappeared (later on, or after a future pregnancy) it is convenient to resume BF.

Since Istubol can suppress postpartum lactation and its excretion into breastmilk is not known, it should be avoided in nursing mothers.

Istubol was more effective than placebo in suppressing lactation and preventing engorgement and pain in two trials in postpartum mothers. Neither study stated what, if any, physical methods (e.g., breast binding) were used concurrently.[1][2] In one study of 80 women, Istubol 10 mg four times daily for 5 days was more effective than placebo in suppressing a rise in serum prolactin after use of a mechanical breast pump after 5 days of treatment, but not on day 3. All of the women in the study had breastfed a previous child.[2] The other study of 150 women used 2 regimens: Istubol 30 mg twice daily for 2 days followed by 10 mg twice daily for 2 days; and 10 mg twice daily for 14 days. More women in the Istubol groups had not previously breastfed an infant.[1] In a case report, a woman with a history of breastfeeding 4 children (the last having been weaned 10 months earlier) began lactating after 1 week of a cancer chemotherapy regimen for breast cancer that included Istubol 20 mg/day. Milk production continued for several weeks until Istubol was discontinued after which it did not return during 12 more weeks of chemotherapy.[3]