Trimethoprim

ACE inhibitors lower aldosterone activity, while spironolactone blocks aldosterone's effect.

Trimethoprim adds another problem by blocking epithelial sodium channels in the distal nephron, producing an effect similar to the potassium-sparing diuretic amiloride.

Severe hyperkalemia with EKG changes requires emergency treatment with IV calcium to stabilize the cardiac membrane, while insulin with glucose can temporarily shift potassium inside cells.

Next up, let's imagine a seventy-eight-year-old woman who develops nausea, unsteadiness, and confusion two weeks after starting hydrochlorothiazide.

Or D, increased insulin release from pancreatic beta cells.

Answer, A, blockade of epithelial sodium channels in the distal nephron.

Trimethoprim has an amiloride-like effect that reduces potassium excretion.

Lisinopril and spironolactone further impair aldosterone-mediated potassium handling, and chronic kidney disease increases the risk.