The Absorption and Excretion of Methyldopa Ingested Concomitantly with Amino Acids or Food Rich in Protein

Abstract

Absorption and urinary excretion of 2-14C-L-.alpha.-methyldopa (.alpha.MD) were investigated in 5 healthy human volunteers. The drug was administered alone, with a mixture of amino acids and with a meal consisting of roast beef. The radioactivity in plasma and urine was not decreased significantly by either treatment, and the overall absorption of the drug was virtually unchanged. The amount of unconjugated .alpha.MD in plasma and urine was significantly decreased following administration of the drug with roast beef. As the acid labile conjugates of .alpha.MD were practically unchanged, an increased biotransformation to other metabolites owing to the protein-rich meal was suggested to be more probable than competition between .alpha.MD and amino acids in the specific transport systems.