|Drug||Examples||Mechanism of Actions||Nursing considerations|
|Thiazide and Related Diuretics||Chlorothiazide (Diuril)|
|Inhibit NaCl reabsorption in the distal convoluted tubule. Increase excretion of Na+ and Cl−. Initial decrease in ECF. Sustained decrease in SVR. Lower BP moderately in 2-4 wk.||Monitor for orthostatic hypotension, hypokalemia, and alkalosis. |
Thiazides may potentiate cardiotoxicity of digoxin by producing hypokalemia.
Dietary sodium restriction reduces the risk of hypokalemia. NSAIDs can decrease diuretic and antihypertensive effect of thiazide diuretics and potentially cause renal impairment.
Advise patient to supplement with potassium-rich foods.
|Loop Diuretics||Bumetanide (Bumex)|
|Inhibit NaCl reabsorption in the ascending limb of the loop of Henle. Increase excretion of Na+ and Cl−. More potent diuretic effect than thiazides, but shorter duration of action. Less effective for hypertension.||Monitor for orthostatic hypotension and electrolyte abnormalities. |
Loop diuretics remain effective despite renal insufficiency. Diuretic effect of drug increases at higher doses.
|Potassium-Sparing Diuretics||Amiloride (Midamor)|
|Reduce K+ and Na+ exchange in the distal and collecting tubules. Reduce excretion of K+, H+, Ca++, and Mg++.||Monitor for orthostatic hypotension and hyperkalemia. |
Contraindicated in patients with renal failure. Use with caution in patients on ACE inhibitors or angiotensin II blockers.
Avoid potassium supplements.
|Aldosterone Receptor Blockers||Spironolactone (Aldactone)|
|Inhibit the Na+-retaining and K+-excreting effects of aldosterone in the distal and collecting tubules.||Monitor for orthostatic hypotension and hyperkalemia. |
Do not combine with potassium-sparing diuretics or potassium supplements. Use with caution in patients on ACE inhibitors or angiotensin II blockers. These drugs are also classified as potassium-sparing diuretics.