Furosemide (Lasix)

Question 1

Drug Classification

Answer 1

Loop diuretic

Question 2

Mechanism of Action

Answer 2

• Enhances vascular prostaglandin synthesis -> decreased intracellular Ca2+ and vascular SMC relaxation -> venous dilation and reduced preload
• binds to chloride binding site on Na+/2Cl-/K+ cotransporter found on the luminal surface of the thick ascending limb of the loop of Henle -> inhibits sodium and chloride reabsorption in the kidneys, thus impacting the osmotic gradient and reducing water reabsorption in the descending limb

Question 3

Pharmacokinetics

• Onset of Action-
• Peak Effects-
• Duration if Effects-
• Half-life-

Answer 3

• Onset of Action-5-10minutes vasodilation, 5-30 minutes diuresis
• Peak Effects-30 minutes vasodilation, 20-60 minutes diuresis
• Duration if Effects- 2 hours vasodilation, 6 hours diuresis
• Half-life- 30 minutes

Question 4

Indications/Field Use

Answer 4

Acute pulmonary edema secondary to CHF

Question 5

Contraindications

Answer 5

Pregnancy/Inability for kidneys to produce urine

Question 6

Side effects/Adverse reactions

Answer 6

HA, Dizziness, hypotension, volume depletion, potassium depletion, dysrhythmias, dehydration, diarrhea, N&V

Question 7

Dose

Answer 7

Adult:
40mg slow IV, IO; if pt takes Lasix daily and took today’s dose, give their dose. If pt didn’t take dose, double daily dose.

Pedi:
0.5-1mg/kg slow IV push (not for children under 12)

Question 8

Precautions

Answer 8

• Protect from light

- Caution with renal failure and sulfa allergies

Question 9

Drug-Drug interactions

Answer 9

May cause additive effects and/or electrolyte imbalance if given with other diuretic. NSAIDs may antagonize effects of Lasix