Renal Pharm - Diuretics Flashcards
Found in saliva
Cations and IgG
(along with proteins, urea, ammonia, enzymes, etc).
How do diuretics alter saliva?
1) They decrease the salivary flow rate (cause xerostomia).
2) Alter pH and buffering capacity.
3) Alter Na and Cl concentrations.
What do Thiazide diuretics inhibit?
Na-Cl symporter
What do loop diuretics inhibit?
Na-K-2Cl symporter
An increase in the formation of urine.
Diuresis
Effect of potassium-sparing diuretics.
Decrease the secretion of potassium, so they’re not good for sinus rhythm of the heart.
Why do people take diuretics?
To increase the excretion of water, thus lowering BP.
Side effect of diuretics
Orthostatic hypotension due to decreased blood volume.
These cells are found in the ascending limb and sense how much Sodium is in the blood.
If there’s too much Na, Na is excreted from the body.
Macula Densa
A loop diuretic that inhibits Na-K-2Cl symporter.
Furosemide (Lasix)
As you go through the loop of Henle and the nephron, less _______ is being reabsorbed into the blood.
Sodium
A potassium-sparing diuretic.
Spironolactone
An aldosterone antagonist.
Spironolactone
Most of the Na gets actively reabsorbed where in the nephron?
Proximal Tubule
What does the Loop of Henle actively transport?
Cotransports Na, K, and 2 Cl.
How does Aldosterone work?
Acts on the distal tubule to increase Na reabsorption, which increases BP.
K+ is excreted in this part of the nephron.
Distal tubule
Where is potassium reabsorbed and excreted?
Reabsorbed in the proximal tubule.
Excreted in the distal tubule.
What does potassium secretion in the distal tubule depend on?
(1) The volume of filtrate
(2) The amount of Na that’s reabsorbed
(3) Aldosterone
The distal tubule has what mechanism for K excretion?
Na/K antiporter
How do diuretics work?
Inhibit Na+ reabsorption, so both Na+ and water are excreted into the urine.
Site of action of diuretics.
Luminal surface of the kidney! IMPORTANT
Site of action of thiazides.
Distal convoluted tubule
Which limb of the Loop of Henle does Furosemide (Lasix) act?
ASCENDING limb
What are Thiazide direutics used to treat?
Swelling in the peripheral appendages.
A risk factor of taking Spironolactone.
Hyperkalemia where there’s too much K+ in the blood because it’s a K+ channel blocker and Aldosterone inhibitor.
This can also cause arrhythmias bc there’s too much K+ in going to the heart.
Can go into cardiac arrest.
Major diuretic effects of Thiazides
1) Increased Na, Cl, and K excretion.
2) HYPOKALEMIA
3) Inhibits Na reabsorption
Minor diuretic effects of Thiazides
1) Increased bicarbonate excretion, so urinary pH INCREASES.
2) Decreased Calcium excretion, so can be used to treat hypercalciURIA.
3) Inhibits uric acid excretion
4) Hyperglycemia
Describe the dose-response curve of Thiazides.
Becomes flat, so they lose the amt of effectiveness after a certain dose is reached.
Side effect of loop diuretics
Hearing impairment (red text)
Action of Furosemide
Inhibits the reabsorption of Na, Cl, K, Mg, and Ca.
Dose response curve of loop diuretics.
STEEP!
Therapeutic uses of loop diuretics.
Pulmonary edema and CHF Edema Hypertension Hyperkalemia Acute renal failure
What does Spironolactone inhibit?
Aldosterone
What kind of diuretic is Spironolactone?
K-sparing
Role of cardiac glycosides
Eliminate K
Role of NSAID’s in BP
Increase BP
Effect of diuretics on Lithium
Na gets excreted while Li gets reabsorbed. Can be toxic.
A potassium sparing diuretic.
Spironolactone
So it inhibits the reabsorption of Na, but prevents the excretion of K.
The function of this diuretic depends on the presence of Aldosterone
Spironolactone
Two types of Potassium-sparing diuretics.
1) Spironolactone
2) Triamterene
Side Effects of Potassium-Sparing Diuretics
HYPERkalemia
Why should you be cautious when taking Lithium and diuretics together?
Since Na is excreted when taking a diuretic, the body reabsorbs more Lithium, leading to toxicity.
