The absorption and metabolism of guanethidine in hypertensive patients requiring different doses of the drug

Abstract

To find out whether difJerences in absorption and metabolism are responsible for the Zarge variation in dose requirement of guanethidine, the quantities of the drug and its metabolites exereted in the urine were measured with the use of a chromatographie method for the separation and quantitative assay of basic drugs in urine. All patients were found to excrete unehanged drug and two metabolites. The percentage of the dose absorbed varied from 3 to 27 per cent, but this was not the only factor determining dose requirement of the drug because the absolute amount of drug absorbed also varied eonsiderably (6.4 to 30 mg. per day).