Deuterated compounds morfinilino

A compound of Formula A ** ** Formula or a salt, hydrate or pharmaceutically acceptable solvate thereof, wherein: R1 is selected from -CH2CH3-, -CH2CD3-, -CD2CH3 and -CD2CD3; each R2 is the same and 10 is selected from H and D; each R3 is the same and is selected from H and D and each R4 is deuterium.