NAPLEX Question of the Week: Order the following...

The NAPLEX has 5 different question formats. Today's question of the week focuses on ordered-response questions.

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Order the following diuretics from beginning to end of a nephron based on where they exert their pharmacologic action in the renal tubular system.

A. Eplerenone

B. Ethacrynic Acid

C. Chlorthalidone

D. Acetazolamide

Answer with Rationale:

The correct order is D-B-C-A. 

As has been detailed in previous question of the week columns, there are 5 ways a question can be asked on the exam. Ordered response involves ranking really about anything in a certain order.

This question in particular can be a bit difficult for a number of reasons. First, you have to know the diuretic in question (by either generic or brand name). I chose the diuretics for this question specifically as they are not Lasix, HCTZ, etc. as they may not be the most well known diuretic. Third, you not only have to know the mechanism of action, you have to know where exactly this takes place because clinically this has an impact on amount of fluid loss exerted by the diuretic at the site of action as well as that diuretic's effect on electrolytes. Therefore the correct order is carbonic anhydrase inhibitor (acetazolamide), loop diuretic (ethacrynic acid), thiazide diuretic (chlorthalidone), and aldosterone antagonists (eplerenone). 

Keep in mind that the order can be asked a number of different ways. This question could have asked for the reverse order and then the correct answer would be the opposite. Be sure and read carefully to ensure you order correctly!

Good luck to many of you as you prepare for the residency interview process as well as your first major job interviews.

Have a great week!

Dr. B

Christopher M. Bland

Clinical Professor, University of Georgia College of Pharmacy

Dr. Christopher M. Bland is a Clinical Professor at the University of Georgia College of Pharmacy at the Southeast GA campus in Savannah, GA. Dr. Bland has over 20 years of academic and clinical experience in a number of clinical areas. He is a Fellow of both the Infectious Diseases Society of America as well as the American College of Clinical Pharmacy. He is co-founder of the Southeastern Research Group Endeavor, SERGE-45, with over 80 practitioners across 14 states involved. Dr. Bland serves as Associate Editor for the NAPLEX Review Guide 4th edition as well as Editor-In-Chief for the Question of the Week. He has provided live, interactive reviews for more than 10 Colleges/Schools of Pharmacy over the course of his career.