Official reprint from UpToDate®
www.uptodate.com ©2017 UpToDate, Inc. and/or its affiliates. All Rights Reserved.

Loop diuretics: Maximum effective dose and major side effects

D Craig Brater, MD
Section Editors
Richard H Sterns, MD
Michael Emmett, MD
Deputy Editor
John P Forman, MD, MSc


Loop diuretics reduce NaCl reabsorption in the thick ascending limb of the loop of Henle. This is achieved by inhibiting the Na-K-2Cl carrier in the luminal membrane in this segment, thereby minimizing the entry of luminal sodium into the cell [1]. The loop diuretics are highly protein-bound and therefore enter the urine primarily by tubular secretion in the proximal tubule, rather than by glomerular filtration [1].

The effect of the loop diuretics is dose dependent, being determined largely by the rate at which the diuretic is delivered to its site of action (figure 1) [2]:

No diuresis is seen with very low doses

A progressively increasing diuresis is achieved at higher doses

A plateau is reached at which even higher doses produce no further diuresis; this dose is called the maximum effective dose, which increases with worsening renal function

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:

Subscribers log in here

Literature review current through: Nov 2017. | This topic last updated: Oct 17, 2017.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2017 UpToDate, Inc.