Loop Diuretic

Diuretics

help your body get rid of extra sodium (Na⁺) and water through urine

-water pills

basic pathway of diuretic

Diuretic → kidneys excrete more Na⁺ → water follows Na⁺ → more urine → less fluid in bloodstream → ↓ blood volume → ↓ blood pressure

edema

swelling caused by too much fluid collecting in the tissues

loop diuretics

make your kidneys get rid of more sodium (Na⁺) and water, causing you to urinate more

-strongest diuretics

loop diuretic drug name

furosemide (lasix)

NKCC2 (Na⁺-K⁺-2Cl⁻)

transports Na, K, and Cl to be reabsorbed back in blood

furosemide pathway

blocks NKCC2 → less Na reabsorption → more Na stay in urine → water follows Na → more urination → less blood volume → less edema and blood pressure

indication of loop diuretic

edema due to heart failure and hypertension

contraindication

anuria (no urine production)

potent diuretics

can cause a large amount of fluid loss

black box warning

potent diuretic that causes loss of lots of fluids and electrolytes

ADR common of loop diuretics

hyperuricemia, hypokalemia, hypomagnesemia, dizziness

hyperuricemia

too much uric acid in blood

hypokalemia

too little potassium in blood

Hypomagnesemia

too little magnesium (Mg²⁺) in the blood.

ADR rare of loop diuretics

Acute Kidney Injury (AKI) and ototoxicity

Acute Kidney Injury (AKI)

excessive fluid loss can reduce blood flow to the kidneys

Ototoxicity

furosemide can damage hearing, particularly at high doses/rapid IV administration

counseling points of loop diuretics

don’t take at night to avoid nocturia and contact doctor if experiencing dizziness/lightheadedness

where does furosemide work?

thick ascending limb of Loop of Henle in nephron