Diuretic Drugs - Ch. 44 Flashcards
Diuresis
Increased water loss
What do diuretic drugs do?
Increase urine output
Remove excess fluid
Accelerate the rate of urine formation
What are first-line diuretics used for?
Heart failure
Hypertension
-acute edematous states
How do most diuretic drugs work?
By excretion of sodium and water
How do diuretics affect blood pressure?
They control sodium and chloride which controls how much water is excreted, and the volume of ECF which controls BP
Sodium controls the movement of what?
Water
-Where sodium goes, water follows
20% to 25% of all sodium is reabsorbed in which part of the nephron?
Loop of Henle
7% of all sodium is reabsorbed in which part of the nephron?
Distal tubules
1-2% of all sodium is reabsorbed in which part of the nephron?
Collecting ducts
What happens if water is not reabsorbed?
It is excreted as urine
What happens when Na reabsorption is blocked?
Excessive fluid loss (dehydration)
Acid-base imbalances
Altered electrolyte levels
What are the types of diuretics?
Loop diuretics
Thiazide and thiazide-like diuretics
Potassium-sparing diuretics
Osmotic diuretics
Which types of diruetics block NaCl reabsorption?
Loop diuretics
Thiazide and thiazide-like diuretics
Potassium-sparing diuretics
What are examples of Loop diuretics?
!! Furosemide (Lasix)
Bumetanide (Burinex)
Ethacrynic acid (Edecrin)
Loop diuretics are also known as?
‘high ceiling’ diuretics
Which part of the nephron do Loop diuretics act in?
Ascending Loop of Henle
What is the mechanism of action of Loop Diuretics?
Inhibits sodium and chloride transporter on luminal membrane so it gets secreted into nephron fluid
Furosemide
Significant diuresis
-Causes significant fluid loss
What does decreased fluid volume cause?
Reduced edema
Reduced venous return (reduced CO)
What is Furosemide used for?
Edema associated with heart failure or hepatic or renal disease
Control of hypertension
Increase renal excretion of calcium in clients with hypercalcemia
What adverse effects are associated with Furosemide?
Excessive fluid loss
-Low Na, Cl
-Water loss —> Dehydration
—> Hypotension
—> thrombosis/embolism
Potassium depletion!! Hypokalemia
Hyperuricemia (may lead to gout)
Hyperglycemia
What levels of potassium are considered hypokalemic?
Below the normal range of 3.5-5mmol/L
How is Hypokalemia treated?
-Treated with K supplements or K-sparing diuretic
Hypokalemia symptoms?
irregular heartbeat
-Potentially fatal dysrhythmias
Muscle weakness/lethargy
Leg cramps
GI disturbances (constipation)
How does Furosemide interact with Digoxin?
Patients need to be monitored for hypokalemia
Increased digoxin toxicity
Increases hypokalemia with other diuretics, glucosteroids
How does furosemide interact with aminoglycosides?
Ototoxicity
How does Furosemide interact with lithium?
May increase the effects of lithium
-Used for bipolar
How does furosemide interact with antidiabetic drugs?
May decrease hypoglycemic effect and cause hyperglycemia