Related Experiment Video
Updated: Oct 4, 2026

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids
Published on: April 25, 2016
Influence of amiodarone on urinary excretion of 6beta-hydroxycortisol in humans
1Department of Pharmacology, Faculty of Medicine, Charles University, Hradec Krdlávé, Czech Republic. micuda@lfhk.cuni.cz
Abstract:
The present study was undertaken to evaluate the use of cortisol 6beta-hydroxylation in defining the effect of amiodarone on cytochrome CYP3A activity. To accomplish this goal, the in vivo activity of CYP3A was estimated by measuring the 24-hour urinary excretion of 6beta-hydroxycortisol (6beta-OHC) and by calculating 24-hour ratio of 6beta-hydroxycortisol to urinary free cortisol (6beta-OHC/UFC ratio). Nine cardiac patients scheduled for amiodarone treatment were recruited to participate in this study. Urine was collected over a 24-hour period from each subject before the first amiodarone administration and during the third day of oral administration of amiodarone (200 mg four times daily as a loading dose). Three days of amiodarone treatment caused a significant decrease (p<0.05) in both the 6beta-OHC/UFC ratio and the 24-hour urinary excretion of 6beta3-OHC. These results suggest that amiodarone is an inhibitor of CYP3A activity.
Related Concept Videos
Renal Drug Excretion: Tubular Secretion
Cushing Syndrome II: Pathophysiology
Time Course of Drug Effect
Renal Drug Excretion: Overview
A nephron consists of two primary structures: the renal corpuscle and the renal tubule. The renal corpuscle contains the glomerulus, a network of capillaries where the first step of renal excretion, glomerular filtration, occurs. Blood pressure forces water, ions, and small molecules out...
Hepatic Drug Excretion: Influencing Factors
Heart Failure Drugs: Inhibitors of Renin-Angiotensin System

