Convert hydrocodone to hydromorphoneCYP2D6 phenotype determines the metabolic conversion of hydrocodone to hydromorphone. . Enzymatic conversion of hydrocodone to hydromorphone is catalyzed by cytochrome P450 2D6, which is inactive in about 7% of Caucasians [poor . . . . A mutation which occurs in approximately 7% of the white population can cause the conversion of hydrocodone to hydromorphone to occur at a negligible rate. . The oral equianalgesic conversion rate (hydromorphone HCl to morphin... more