Question: What are the benefits and side effects of an aldosterone antagonist?
Answer: Thanks to research led by Dr. Betram Pitt from my institution, University of Michigan, we now know that aldosterone anatagonists can prolong survival, reduce hospitalizations, and improve symptoms of heart failure in patients with moderate to severe chronic systolic heart failure, as well as in patients who have heart failure early after a heart attack.
Aldosterone antagonists can sometimes cause harmful side effects. They can cause breast tissue to enlarge and become tender both in men and in women. They can also cause erectile dysfunction in men and problems with menstrual periods in women. All these symptoms are reversible on discontinuation of spironolactone. There's another aldosterone antagonist that's newer and somewhat more expensive called eplerenone that tends not to cause these side effects.
Now, both spironolactone and eplerenone can cause kidney dysfunction and high potassium levels. We have to monitor for these in order to use the drug safely. And we don't use the drug in patients who already have significant kidney dysfunction or have elevated potassium levels.