Epithelial Sodium Channel Blockers

Amiloride and triamterene block membrane bound epithelial sodium channel (ENaC) in the DCT & cortical collecting tubule of the kidney.  Blockage of ENaC diminishes sodium reabsorption and potassium excretion.  These medications have off-label usage in cirrhosis.   These drugs increase uric acid levels as well as increased risk of kidney stones.  Hyperkalemia is most common and can be dangerous.  

Class Drugs

• Amiloride

• Triamterene

Class Mechanism of Action

Blocks sodium transport channel in distal convoluted tubules & cortical collecting ducts

• Reduces Na reabsorption

• Retains K and H ions (potassium-sparing)

Renal Tubule - Primary sites of action of diuretics.

Class Applications

Hypertension

Heart Failure

• Given in conjunction with thiazide diuretic to counteract potassium wasting

Class Adverse Effects

• Increased Uric Acid

• Nephrolithiasis (kidney stones)

• Hyperkalemia

Drug Table

Drug Name	Application	Comments	Image
Amiloride			"Amy in a lowrider car"
Triamterene			"Tram" "Tearing"