It also says that no side effects have been reported in babies who have had exposure to the medication through milk, but to watch for sedation, apnea, and constipation (as things that are potential concerns, but haven't been reported in real world cases).
Most authors suggest that doses of 5 mg every 4 hours or more has a minimal effect on nursing infants, particularly older infants. However, no data on hydrocodone levels in milk are available. To reduce exposure of the infant, attempt to feed infant prior to taking the medication. Neonates may be more sensitive to this product, observe for sedation or constipation.