Amiloride and Quinapril and hydrochlorothiazide interaction

Hyperkalemia occurs commonly (about 10%) when amiloride is used without a kaliuretic diuretic.

When amiloride HCl is used concomitantly with a thiazide diuretic in patients without these complications, the risk of hyperkalemia is reduced to about 1-2 percent.

It is thus essential to monitor serum potassium levels carefully in any patient receiving amiloride, particularly when it is first introduced, at the time of diuretic dosage adjustments, and during any illness that could affect renal function.

The risk of hyperkalemia may be increased when potassium-conserving agents, including amiloride HCl, are administered concomitantly with an angiotensin-converting enzyme inhibitor, an angiotensin II receptor antagonist, cyclosporine or tacrolimus.

Diabetes Mellitus In diabetic patients, hyperkalemia has been reported with the use of all potassium-conserving diuretics, including amiloride HCl, even in patients without evidence of diabetic nephropathy.

…sometimes associated with oliguria and/or progressive azotemia, and rarely acute renal failure and/or death, include patients with the following conditions or characteristics: heart failure, hyponatremia, high dose diuretic therapy, recent intensive diuresis or increase in diuretic dose, renal dialysis or severe volume and/or salt depletion of any etiology.

The thiazide component of quinapril and hydrochlorothiazide tablets may potentiate the action of other antihypertensive drugs, especially ganglionic or peripheral adrenergic- blocking drugs.

Such patients should be followed closely for the first 2 weeks of treatment and whenever the dosage of quinapril or diuretic is increased.

In clinical studies in hypertensive patients with unilateral renal artery stenosis, treatment with ACE inhibitors was associated with increases in blood urea nitrogen and serum creatinine; these increases were reversible upon discontinuation of ACE inhibitor, concomitant diuretic, or both.

Some quinapril-treated hypertensive patients with no apparent preexisting renal vascular diseases have developed increases in blood urea nitrogen and serum creatinine, usually minor and transient, especially when quinapril has been given concomitantly with a diuretic.