- Patient, if female and breastfeeding; NOTE: It is not known whether STI571or its metabolites are excreted in human milk; however, in lactating female rats administered 100mg/kg, a dose approximately equal to the maximum clinical dose of 800mg/day based on body surface area, STI571 and /or its metabolites were extensively excreted in milk; it is estimated that approximately 1.5% of a maternal dose is excreted into milk, which is equivalent to a dose to the infant of 30% the maternal dose per unit body weight; women should be advised against breastfeeding while taking STI571