In Women of all ages with typical codeine metabolism (standard CYP2D6 activity), the level of codeine secreted into human milk is minimal and dose-dependent. There isn't any information on the effects from the codeine on milk production. Promethazine is metabolized because of the liver to a range of inactive metabolites https://akorn-codeine02233.activablog.com/31527225/rumored-buzz-on-akorn-promethazine-codeine