Acetaminophen Elimination Half-Life in Humans Is Unaffected by Short-Term Consumption of Sulfur Amino Acid-Free Diet

Sulfation and glutathione (GSH) conjugation are important pathways for elimination of acetaminophen (APAP). Previous studies in rodents show that limitation of dietary sulfur amino acids (SAAs) reduces biosynthesis of 3-phosphoadenosine-5-phosphosulfate, the precursor for sulfation, and GSH, the pre-cursor for the mercapturatic acid pathway. The amount of SAA needed for the metabolism of two doses of APAP is equivalent to 62 % of the recommended dietary allowance (RDA) for SAA in humans. A decrease in the activity of these metabolic pathways could lead to decreased elimination of the reactive metabolite of APAP and possibly affect risk of APAP use. To determine whether intake of a SAA-deficient diet alters APAP metabo-lism, a pilot clinical study with a double-blind, cross-over design was performed. Subjects received the RDA for SA