Scant appreciation for the pharmacological properties of various diuretics leads to their use in a “stereotypical manner” that is both less efficacious and riskier, according to David Ellison, professor of Medicine and Physiology and Pharmacology, director of the Oregon Clinical and Translational Research Institute.¹
Recall that diuretics are classified according to their predominant site and mechanism of action along the nephron.
Loop (of Henle) Diuretics
Organic ions which, except for ethacrynic acid, act from the lumen to inhibit Na-K-2Cl cotransporter (NKCC2) along thick ascending limb and macula densa
- furosemide
- bumetanide
- torsemide
- ethacrynic acid (acts within cell – i.e. does not require secretion into lumen)
side effects: hypersensitivity, ECF volume depletion, hypokalaemic alkalosis, hypomagnesemia, ototoxicity
Distal Convoluted Tubule
Organic ions that luminally bind thiazide-sensitive NaCl cotransporter (NCC) along the distal convoluted tubule (DCT)
- thiazides
- thiazide-like
side effects: hypersensitivity, hyponatraemia, hypokalaemic alkalosis, hyperglycaemia, hyperuricaemia, hypomagnesemia, (hypokalemia and prerenal azotemia in combination with loop diuretics)
Potassium-sparing diuretics
- apical sodium-channel blockers
- amiloride
- triamterene
- mineralocorticoid blocker (act within cells – no secretion into lumen required)
- spironolactone
- epleronone
- non-steroidal mineralocorticoid blocker (act within cells – no secretion into lumen required)
side effects: hypersensitivity, hyperkalaemia, metabolic acidosis, azotemia, gynaecomastia, (vaginal bleeding – spironolactone)
Further Reading
Joannidis, Michael, Sebastian J Klein, and Marlies Ostermann (2019). 10 myths about frusemide. Intensive Care Med https://doi.org/10.1007/s00134-018-5502-4
Reference
- Ellison, David H & Ellison, David H (2019) Clinical Pharmacology in Diuretic Use. Clinical journal of the American Society of Nephrology : CJASN. [Online]. Available from: http://search.proquest.com/docview/2202196330/.
