Precursor to metabolite: Bupropion XL 450 mg to Hydroxybupropion

Bupropion XL 450 mg is converted to Hydroxybupropion by CYP2B6.

The pair

Bupropion XL 450 mg — Bupropion XL as a single 450 mg tablet, for patients stabilized at the maximum dose.
Hydroxybupropion — Bupropion's principal active metabolite; largely noradrenergic and present at higher concentrations than the parent.

Anything that inhibits or induces CYP2B6 shifts the balance between Bupropion XL 450 mg and Hydroxybupropion.