Interference by Formaldehydogenic Drugs in the Quantitative Determination of Urinary Hydroxyindoleacetic Acid

[摘要] The administration of methenamine mandelate (Mandelamine) to normal individuals and patients with carcinoid resulted in a marked reduction in apparent urinary hydroxyindoleacetic acid (HIAA) as determined by the quantitative nitroso-naphthol method. Mandelamine, methenamine, and formaldehyde inhibited the normal color development in vitro. The interfering reaction is dependent on an acid pH and is not reversed by raising the pH. It is suggested that formaldehyde is the active substance and the role of mandelamine and methenamine is that of a precursor of this substance in acid solution. Chloride and sulfate ions, per se, caused a definite but limited interference with the color reaction. Under the conditions of this study, mandelamine did not prevent detection of elevated urinary HIAA by the qualitative test for HIAA.

[学科分类] 过敏症与临床免疫学