acetylator

noun

acet·​y·​la·​tor ə-ˈse-tə-ˌlā-tər 

: an organism that acetylates a substance during metabolism

—used especially to describe the rate at which a person acetylates certain drugs (such as isoniazid, hydralazine, or sulfamethazine) in the body

People known as slow acetylators, for instance, take a longer time than fast acetylators to clear certain drugs from the liver.

—Robin Marantz Henig, The New York Times

Note: The variation among acetylators has been shown to be genetically determined. Slow acetylators may experience undesirable side effects resulting from higher drug concentrations in the body.