Loop diuretics contraindications

Loop diuretics are contraindicated in patients with known hypersensitivity to the loop diuretics or to the sulfonamides, severe electrolyte imbalances, hepatic coma, or anuria, and in infants (ethacrynic acid). 

Hypercalcemic crisis and symptomatic hypercalcemia are medical emergencies requiring immediate treatment. Rehydration with normal saline followed by loop diuretics can be used in patients with normal to moderately impaired renal function. Initiate treatment with calcitonin in patients in whom saline hydration is contraindicated (Table 78-3). 

Contraindications Hypersensitivitytocarbonicanhydraseinhibitors, local anesthetics, salicylates, sulfonamides, sulfonylureas, sunscreens containing PABA, or thiazide or loop diuretics intestinal or urinary tract obstruction porphyria severe hepatic or renal dysfunction... 

Amiloride is used with thiazide or loop diuretics in hypertension, in congestive heart failure, in digitalis-induced hypokalemia, and in arrhythmias resulting from hypokalemia. Inappropriate use of amiloride may cause hyperkalemia (potassium >5.5 mEq/L), which may be fatal if not corrected, and may be more deleterious in elderly individuals and in patients with diabetes mellitus and renal impairment. The symptoms of hyperkalemia include fatigue, flaccid paralysis of the extremities, paresthesias, bradycardia, ECG abnormalities, and shock. Amiloride is not metabolized but is contraindicated in anuria, acute or chronic renal insufficiency, or in diabetic nephropathy. It should not be used with potassium preparations, and should be used cautiously with ACE inhibitors because these agents cause hyperkalemia. 

Contraindications to the use of loop diuretics include severe Na+ and volume depletion, hypersensitivity to sulfonamides (for sulfonamide-based loop diuretics), and anuria unresponsive to a trial dose of loop diuretic. 

A list of loop diuretic drugs is provided in the Appendix. Detailed tables show doses, recommendations, expectations, side effects, contraindications, and more available on the book s Web site (see URL in Appendix). 

On the basis of the above findings, the manufacturer contraindicates the use of dofetilide with hydrochlorothiazide alone or in combination with triamterene. Given the increase in QT interval, a risk factor for torsade de pointes arrhythmia, this appears a prudent precaution. Further study is needed. Any diuretic that depletes serum potassium (such as the loop diuretics) might be expected to increase the risk of QT prolongation and torsade de pointes with dofetilide, and serum potassium should be monitored. ... 

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