Furosemide
UW Health
Emergency Education Center
Paramedic Training
Generic Name Furosemide
Trade name
Lasix
Classification Diuretic
Mechanism of action:
Inhibits re absorption of Na and Cl in the proximal and distal tubules
and in the loop of Henle -diuretic effect seen 15 – 20 minutes]
Dilates systemic venous compartment- decreases preload by increasing
venous capitance [vascular effects can be seen in 5 min}
Decreases intravascular volume
Decreases cardiac output
Indications
Acute pulmonary edema (usually not used emergently anymore)
Edema secondary to CHF
Hypertension
Increased ICP
Contraindications
Sulfonamide sensitive persons may be allergic to furosemide
Acute renal failure patients or dialysis patients who cannot produce urine
Hypersensitivity to furosemide
Hypovolemia
Hypotension: Consider SBP “cut-off” of ~ 90; contact medical control
Electrolyte depletion
Adverse Effects
Postural hypotension
Hypotension
Tinnitus [ringing in ears] with irreversible deafness [ototoxicity] which is related
to dosage AND rate of injection
Nausea and vomiting
Hyperglycemia
Bladder distension
ECG changes with changes in electrolytes [monitor patient]
Cause electrolyte imbalances: Decrease in K, Na, Cl, Ca
Dry mouth
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Furosemide
May potentate other medications
Digoxin ( due to K depletion )
Lithium due to reduced clearance leading to lithium toxicity
Aminoglycosides have increased ototoxic potential
Precautions
1.
2.
3.
4.
Pregnancy, unless life threatening
Electrolyte abnormalities if patient takes oral diuretics
Hypotension [ cardiac output may lead to coronary artery perfusion]
Hypovolemia or dehydration
Dosage
Initial dose 0.5 – 1 mg/Kg given over 1 – 2 minutes
If no response, double dose 2 mg/Kg slowly over 2 minutes, 1-2 hours later[controversial]
Effects of a too large dose may lead to water and electrolyte depletion or circulatory
collapse
Administration
IV bolus injected slowly over 1-2 minutes
IM rarely used
PO
Miscellaneous information
Action times with IV administration
Onset of vascular effects within 5 minutes
Diuresis occurs 15 – 20 minutes later
Peaks in 30 minutes
Duration is 2 hours
Protect from light
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