STUDIES ON C-13-PHENACETIN METABOLISM .2. A COMBINATION OF BREATH TEST AND URINE TEST OF IN-VIVO METABOLITES IN THE DIAGNOSIS OF LIVER-DISEASE

We determined the optimum C-13-labeling position in phenacetin for use in a breath test to diagnose liver disease based on infrared spectros copy detection of (CO2)-C-13 in exhaled air, ([1-C-13]Ethoxy)phenaceti n gave the best result, This compound was also employed in a urine tes t using C-13-NMR spectroscopy, In the urine test, healthy subjects gav e a higher signal of phenacetin than of its metabolite, phenetidine, w hereas in patients with liver disease the situation,vas the reverse, T he combination of the breath and urine tests mag be a valuable new too l for the diagnosis of liver disease.