The pH‐dependent excretion of mono methylated tricyclic antidepressants; In dog and man

Abstract

After intravenous administration of desmethylimipramine and nortriptyline to dogs, the excretion of unchanged drug in urine or gastric juice was found to be of little quantitative importance. The renal excretion was pH dependent, indicating nonionic diffusion between blood and urine. The urinary excretion of desmethylimipramine or nortriptyline given in therapeutic doses to depressed patients was also shown to be pH dependent. At a steady‐state plasma level of the antidepressant drugs, less than 5 per cent of the daily dose was excreted unchanged through the kidney. These data are discussed in relation to the treatment of tricyclic drug intoxications.