5. Spironolactone

Question 1

Drug class

Answer 1

aldosterone receptor antagonist

Question 2

What is it used for?

Answer 2

hypertension

step 4 - resistant hypertension

Question 3

Mechanism of action

Answer 3

block aldosterone receptors, therefore reducing the reabsorption of sodium and water from the kidney to reduce BP.

Question 4

Important adverse drug reactions

Answer 4

Hyperkalaemia, gynaecomastia

Question 5

Important drug-drug interactions

Answer 5

↑K+ drugs (monitoring) e.g, ACEi and ARB, pregnancy

Question 6

warnings, contraindications

Answer 6

Hyperkalaemia, Addison’s

Question 7

what is gynaecomastia?

Answer 7

a condition by which males develop breast tissue due to an imbalanced ratio of oestrogen and androgen activity

Question 8

why does spironolactone cause gynaecomastia?

Answer 8

> decreases testosterone production

> increases peripheral conversion of testosterone to estradiol,

> displaces estradiol from sex hormone-binding globulin.