Methods for the determination of N-methyl-2-pyridone-5-carboxylamide and of N-methyl-2-pyridone-3-carboxylamide in human urine

Abstract

Methods are described for the detn. of N-methyl-2-pyridone-5-carboxylamide and N-methyl-2-pyridone-3-carboxylamide in human urine. Results are shown which indicate that the 2,3-amide is of no significance in nicotinic acid metabolism, but that the 2,5-amide is an important metabolite. The 2,5-amide was excreted by 2 normal adults in amts. of the order of 7 mg./24 hr.. After the ingestion of 500 mg. of nicotinamide, the urinary excretion of the 2,5-amide increased greatly, 47-57% of the dose being excreted in 72 hrs. as the latter compound. It was possible to account for 73-80% of an orally administered dose of 500 mg. of nicotinamide in the urine of 2 adult subjects as N-methyl-2-pyridone-5-carboxylamide, N-methylnicotinamide and the total acid-hydrolyzable derivatives of nicotinic acid.