Loop Diuretics

Loop diuretics enhance urinary potassium excretion to counteract serum potassium load and can be used in patients with residual kidney function. This increases sodium delivery to the distal tubule which creates an electronegative gradient that favors potassium secretion into the tubule.

1. Furosemide

• Mechanism of Action: Renal K+ excretion
• Dose: Intravenous, 40-80 mg
• Pharmacokinetics:
  • Onset of Action: 2-4 hours
  • Duration of Effect: Varies
• Contraindications: Hypovolemic patients
• Adverse Effects: Hypovolemia, hypokalemia, hypomagnesemia
• Pearls: Efficacy of Furosemide diminishes in patients with severe kidney failure and risk of hypotension outweighs potential benefits; may be combined with thiazides or acetazolamide; K+ removed from the body: Variable