A person classified as an ultrarapid metabolizer (UM) has a polymorphism that enhances the catabolic activity of the enzyme. This means that a UM would need more of the drug to achieve a 'normal' level since he/she is rapidly metabolizing the drug.

Chem

In therapeutic drug monitoring, a person who is classified as an ultrarapid metabolizer (UM) would need __________ of a drug metabolized by that enzyme.