Published in Pediatrics and Child Health , a Canadian Pediatrics Journal is this case report of a newborn requiring 2 months of morphine withdrawal. I have not heard of kratom from the tropical Mitragena speciosa tree, mitragynine the likely active ingredient. In low doseage it produces a stimulant effect and at higher doses sedation and nausea. Respiratory depression is not a feature.
It is a regulated Herbal Product in the USA, but illegal to sell in Canada. There is easy internet availability however.