Spironolactone Pharmacology Podcast

Spironolactone, branded as Aldactone, serves as a potassium-sparing diuretic and aldosterone antagonist that effectively manages refractory hypertension, heart failure, and edema. By blocking aldosterone receptors, the medication facilitates sodium and water excretion while retaining potassium, a mechanism that necessitates careful monitoring to avoid hyperkalemia. Clinical applications extend beyond cardiovascular health to include the treatment of ascites—often using a specific 100:40 ratio with furosemide to balance electrolyte levels—as well as off-label uses for acne and female hair loss due to its antiandrogenic properties. Key safety considerations include avoiding use in patients with an EGFR below 30 or baseline potassium above 5 mEq/L. Notable adverse effects include dose-dependent gynecomastia, orthostatic hypotension, and potential hyponatremia. Furthermore, significant drug interactions occur with ACE inhibitors, ARBs, and trimethoprim, all of which can synergistically elevate potassium to dangerous levels.