Diuretics Flashcards
What is the general physiological outcome of diuretics?
Increased urine output by decreasing the reabsorption of sodium (Na+), chloride (Cl-), bicarbonate (HCO3-), or other ions.
How do diuretics promote water excretion?
By increasing the excretion of specific ions, changing osmotic balance.
What is the primary mechanism of diuretics?
They act on different parts of the nephron to inhibit ion transport, reducing water reabsorption.
How do diuretics help in Nephrotic Syndrome?
They reduce fluid retention caused by albumin loss.
What condition does diuretic use improve in Congestive Heart Failure (CHF)?
Reducing blood volume.
What is the role of diuretics in Renal Failure?
They prevent excess sodium retention.
How do diuretics help in Hepatic Cirrhosis?
They reduce ascites (fluid in the peritoneal cavity).
How do diuretics help in Hypertension?
They lower blood pressure by reducing blood volume.
What effect do diuretics have on Nephrolithiasis (Kidney Stones)?
Thiazides reduce calcium in urine, preventing stone formation.
How are diuretics used in Hypercalcemia?
Loop diuretics increase calcium excretion.
How do diuretics help in Nephrogenic Diabetes Insipidus (NDI)?
Thiazides reduce excessive urine production.
What are the therapeutic uses of diuretics?
Edematous state (fluid retention)
- CHF
- Kidney disease
- Hepatic cirrhosis
- Idiopathic edema
Non-Edematous state (no fluid retention)
- Hypertension
- Kidney Stones
- Hypercalcemia
- NDI
Where does the initial ultrafiltration occur in the nephron?
Glomerulus.
Which diuretics act on the Proximal Tubule?
Osmotic diuretics and carbonic anhydrase inhibitors.
What part of the nephron is targeted by loop diuretics?
Loop of Henle (Thick Ascending Limb).
Which diuretics act on the Distal Convoluted Tubule?
Thiazide diuretics.
Which diuretics target the Collecting Duct?
Potassium-sparing diuretics.
Name two osmotic diuretics.
Mannitol (Osmitrol®), Urea (Ureaphil®).
What is the mechanism of osmotic diuretics?
Increases osmolarity of tubular fluid, preventing water reabsorption.
What is the effect of osmotic diuretics?
Increased excretion of water and some electrolytes.
What are the therapeutic uses of osmotic diuretics?
Acute renal failure, reduction of intracranial pressure, excretion of toxic substances.
Name three carbonic anhydrase inhibitors.
Acetazolamide (Diamox®), Dichlorphenamide (Daranide®), Methazolamide.
What is the mechanism of carbonic anhydrase inhibitors?
Inhibits carbonic anhydrase, decreasing HCO3- reabsorption and reducing Na+/H+ exchange, reducing Na+ reabsorption
What is the effect of carbonic anhydrase inhibitors?
Increased excretion of Na+, HCO3-, and water (weak action) bascially decrease the reabsorption
What are the uses of carbonic anhydrase inhibitors?
Glaucoma, acute mountain sickness, metabolic alkalosis, epilepsy.
Name four loop diuretics.
Furosemide (Lasix®), Bumetanide (Bumex®), Ethacrynic Acid (Edecrin®), Torsemide (Demadex®).
What is the mechanism of loop diuretics?
Inhibits Na+/K+/2Cl- co-transporter (NKCC2), reducing reabsorption of Na+, Cl-, Ca++, and Mg++.
What is the effect of loop diuretics?
Increased excretion of Na+, Cl-, Mg++, and Ca++.
What are the uses of loop diuretics?
Edema (CHF, hepatic, renal disease, ascites), hypertension, hypercalcemia.
Name two thiazide diuretics.
Hydrochlorothiazide (Hydrodiuril®), Chlorothiazide (Diuril®).
What is the mechanism of thiazide diuretics?
IInhibits Na+/Cl- co-transporter (NCCT), increases calcium reabsorption.
What is the effect of thiazide diuretics?
Increased excretion of Na+ and Cl-, increased calcium reabsorption.
What are the uses of thiazide diuretics?
Hypertension
adjunct therapy for CHF
nephrogenic diabetes insipidus
kidney stone prevention
Name two types of potassium-sparing diuretics.
Aldosterone Antagonists (Spironolactone), Sodium Channel Blockers (Triamterene, Amiloride).
What is the mechanism of aldosterone antagonists?
Block aldosterone receptors, reducing Na+ reabsorption and K+ excretion.
What is the effect of aldosterone antagonist potassium-sparing diuretics?
Increased Na+ excretion, decreased K+ excretion.
What is the mechanism of sodium channel blockers?
Directly inhibit Na+ channels in the collecting tubule. (decreased Na+ absorption)
What are the uses of potassium-sparing diuretics?
Used with loop or thiazide diuretics to prevent K+ loss, hypertension, and heart failure.
