Which antibiotic does not undergo acetylation?

Which antibiotic does not undergo acetylation?

• A. Isoniazid
• B. Chloramphenicol
• C. Hydralazine
• D. Sulfonamides

Answer: (B)

Acetylation is a common metabolic step done by N-acetyltransferase enzymes that can alter a drug’s activity and how long it stays in the body. Isoniazid, hydralazine, and sulfonamides are classic substrates of this pathway, so their levels and effects are often influenced by the acetylator status of a person. Chloramphenicol, on the other hand, is mainly eliminated by glucuronidation in the liver rather than by acetylation. The acetylation of chloramphenicol does occur in bacteria via chloramphenicol acetyltransferase, which is a resistance mechanism, but that’s not a primary human metabolic route. So, in human drug metabolism, this antibiotic does not undergo acetylation as a major pathway.

Acetylation is a common metabolic step done by N-acetyltransferase enzymes that can alter a drug’s activity and how long it stays in the body. Isoniazid, hydralazine, and sulfonamides are classic substrates of this pathway, so their levels and effects are often influenced by the acetylator status of a person.

Chloramphenicol, on the other hand, is mainly eliminated by glucuronidation in the liver rather than by acetylation. The acetylation of chloramphenicol does occur in bacteria via chloramphenicol acetyltransferase, which is a resistance mechanism, but that’s not a primary human metabolic route. So, in human drug metabolism, this antibiotic does not undergo acetylation as a major pathway.