Loop Diuretics Lecture Notes

Introduction

• Loop diuretics are medications used to remove excess fluid in the body quickly.
• Commonly used for peripheral and pulmonary edema.
• Visual mnemonic: Loop-de-loop roller coaster symbolizes loop diuretics.

Key Drug Names

• Furosemide: Remembered by 'fur' (girl in fur coat) – generic name tested on NCLEX, trade name is Lasix.
• Torsemide: Symbolized by a 'tour guide' (sounds like torsemide).
• Bumetanide: Represented by a 'boombox' (boom for bumetanide).
• Additional: Ethocrinic acid – less common, not emphasized for memorization.

Mechanism of Action

• Block sodium and water transport at the ascending loop of Henle in kidneys.
• Cause reduced ion absorption and increased water loss into urine.
• Fast onset: Acts within 30 minutes to 1 hour; useful for rapid fluid loss in emergencies.

Clinical Uses

• Treat conditions with volume overload:
  • Peripheral edema
  • Pulmonary edema
  • Hypertension
  • Ascites

Nursing Considerations

• Avoid administering diuretics in the evening to prevent nighttime bathroom trips.
• Ensure patients have easy bathroom access; monitor urine output carefully.
• Report urine output < 30 mL/min – may indicate a serious condition.

Adverse Effects

• Ototoxicity: Risk of damage to inner ear (manifesting as hearing loss or ringing due to loud boombox symbol).
  • Risk increases with high drug levels or fast administration.
  • Monitor and adjust dose or delivery rate if needed.
• Hypokalemia: Drop in potassium levels (banana symbolizes potassium).
  • Avoid in patients with low potassium (< 3.5 mEq/L).
  • Supplement with potassium and encourage potassium-rich foods.

Summary

• Loop diuretics increase urine output to cause fluid loss.
• Act on loop of Henle to inhibit sodium reabsorption, causing water loss.
• Most common drugs: Furosemide, torsemide, bumetanide.
• Treat fluid overload conditions: Pulmonary and peripheral edema, ascites.
• Side effects include ototoxicity and hypokalemia.

Conclusion

• Loop diuretics are powerful agents for treating fluid overload.
• Important for nurses to manage administration and monitor adverse effects.
• Remember visual mnemonics to associate drug names and effects.