Diuretics Flashcards by Adam B

What are the Thiazides diuretics?

hydrochlorothiazide Metolazone Chlorthalidone

How well did you know this?

Not at all

Perfectly

What are the loop diuretics (edema, hypertension)?

-semide

Furosemide (biggy)
Torsemide
Bumetanide
Ethacrynic Acid (only one that isn’t a sulfa drug)

How well did you know this?

Not at all

Perfectly

What are the K+ sparing diuretics (edema, hypertension). Specifically, Na+ channel blockers?

Amiloride Triamterene

How well did you know this?

Not at all

Perfectly

What are the K+ sparing diuretics (edema, hypertension), specifically aldosterone antagonists?

(Also as antifibrotic in heart failure)

Spironolactone
Eplerenone

How well did you know this?

Not at all

Perfectly

What are the aquaretics (hyponatremia)

-vaptan Conivaptan Tolvaptan MOA: Inhibit ADH receptors

How well did you know this?

Not at all

Perfectly

What are the Carbonic Anhydrase inhibitors? What are the used to treat?

Acetazolamide

urinary alkalinization (ex. ASA overdose trapping in lumen)
Mountain sickness (you blow off CO2 because of altitude, acetazolamide gets ride of bicarbonate to balance things out)
Glaucoma

How well did you know this?

Not at all

Perfectly

Osmotic diuretics maintain urine flow by pulling water from cells for excretion. What are their names?

Mannitol

How well did you know this?

Not at all

Perfectly

What’s the difference between a natriuretic and an aquaretic?

Natriuretic: diuretic that promotes renal excretion of sodium Aquaretic: diuretic that promotes free water clearance

How well did you know this?

Not at all

Perfectly

Where do osmotic diuretics act within the nephron?

Proximal tubule Thin descending limb of Henle

How well did you know this?

Not at all

Perfectly

Where do carbonic Anhydrase inhibitors act within the nephron?

Proximal tubule

How well did you know this?

Not at all

Perfectly

Where do loop diuretics act on in the nephron?

Thick ascending limb of Henle

How well did you know this?

Not at all

Perfectly

Where do thiazide diuretics act in the nephron?

Distal convoluted tubule

How well did you know this?

Not at all

Perfectly

Where do Na+-channel blockers act on the nephron?

Cortical collecting duct

How well did you know this?

Not at all

Perfectly

Where do vaptans act on the nephron?

Collecting duct:

Prevents ADH-mediated insertion of aquaporins into the membranes of principle cells

How well did you know this?

Not at all

Perfectly

The majority of diuretics are of what type?

Natriuretics

How well did you know this?

Not at all

Perfectly

What are common clinical reasons for administering diuretics?

Essential hypertension
Edema (CHF, liver failure, kidney failure)

How well did you know this?

Not at all

Perfectly

What are the K+ sparing diuretics?

Triamterene (Na+ channel blocker)
Amiloride (Na+ channel blocker)
Spironolactone (aldosterone antagonist)

How well did you know this?

Not at all

Perfectly

What are the K+ losing diuretics?

Thiazides (Na+ Cl- cotransporter blockers)
Loop diuretics (Na+ K+ 2Cl- cotransporter blockers)
Carbonic Anhydrase inhibitors (seldom used)
Osmotic diuretics (non reabsorbable solutes)

How well did you know this?

Not at all

Perfectly

What are two concerns of hyperkalemia?

Tall T waves

Arrhythmias:

Bradycardia
Ventricular tachycardia Fibrillation

How well did you know this?

Not at all

Perfectly

Gives the greatest amount of diuresis. Sulfa type drugs.

Loop diuretics

How well did you know this?

Not at all

Perfectly

What is the mechanism of action of loop diuretics?

MOA: Blocks the Na+-K+-2Cl- cotransporter in the thick ascending limb of Henles’s Loop

Diuretic that causes the greatest HCO3- loss?

Thiazide diuretics

What are the therapeutic uses of Thiazides?

Hypercalcemia:

osteoporosis tx
recurrent calcium kidney stone tx

Primary hypertension (combined w/ other drugs)
Paradoxically treats nephrogenic diabetes insipidus
Synergistic effects w/ loop diuretics

What type of urine do Loop Diuretics (Furosemide) produce regardless if the patient is excreting concentrated or already dilute urine?

Large volumes of isotonic urine

max doses produce profound diuresis

What is another common name for Furosemide a loop diuretic?

Lasix

What are the indications for Loop Diuretics?

* Edema of hepatic, cardiac, or renal origin * **Acute pulmonary edema** (removes EC fluid \<30 min) * Furosemide produces a prostaglandin effect (venodilation —\> reduced preload) **When rapid and massive fluid removal is needed**

What is an additional benefit of Furosemide aside from its actions as a diuretic?

Thought to mediate prostaglandin-mediated venodilation **reducing preload**

Pt presents hypertensive and a thiazide diuretic is indicated, but GFR is too low (\< 30mL/min) and a thiazide diuretic won’t work. What can you use instead?

Loop Diuretic (Furosemide) Still works when **RBF and GFR are low**

What are the adverse effects of Loop Diuretics?

* **Hyponatremia** * **hypochloremia** * **Hypovolemia & hypotension** * **Hypocalcemia** (result of hypokalemia) —\> kidney stone formation * **Hypomagnesemia** (result of hypokalemia) * hyperglycemia **Hypokalemia** (potassium losing diuretic): * Na+ reabsorbed using a K+/H+ exchanger leading to **hypochloremic metabolic alkalosis**

What are drug interactions to loop diuretics?

* Digoxin (Digoxin and LDs lower K+) digoxin is a competitive inhibitor of K+ in the heart * ototoxic drugs - risk of hearing loss * potassium-sparing diuretics

What is the MOA of thiazides?

Blocks the Na-Cl cotransporter in the distal convoluted tubule * **Thiazides result in severe magnesium wasting**

What diuretic doesn’t function well with a low GFR (\< 30 mL/ ) and low RBF?

Thiazide diuretics

What are the adverse effects of Thiazide diuretics?

* **hypochloremic metabolic alkalosis** * **hypomagnesia**

What are the drug interactions to be conscious of with Thiazide diuretics?

increases risk of **digoxin** and **lithium toxicity**

in terms of ion excretion what are the major differences between thiazides and loop diuretics?

Thiazides as compared to loop diuretics: * less Na+ excretion * less K+ excretion * more bicarbonate excretion

What is the MOA of amiloride and triamterene?

K+ sparing diuretics (Na+ channel blockers) blocks luminal Na+ channels (ENaC) in the collecting duct

What is the MOA of spirinolactone and eplerenome?

K+ sparing diuretic (aldosterone receptor blocker) blocks aldosterone receptors in the colleting duct

What is the therapeutic use of triamterene?

K+ sparing diuretic (Na+ channel blocker) * tx: hypertension * tx: edema

What are the adverse effects of triamterene?

K+ sparing diuretic (Na+ channel blocker) * **hyperkalemia** * nausea, vomiting, leg cramps, and dizziness

What's the key difference between K+ sparing diuretics: Na+ channel blockers vs aldosterone antagonists?

aldosterone antagonisits such as **spironolactone** is a steroid and can take **48 hours to work**. Na+ channel blockers are much more **immediate**

Known to greatly reduce mortality rate in patients with severe heart failure due to decreasing myocardial fibrosis and reducing early morning rises in heart rate

Spironolactone

What are adverse effects of the K+ sparing diuretic Spironolactone?

* Hyperkalemia Endocrine effects: * **Gynecomastia - major differentiation from Eplerenone (not seen w/ eplerenone use)** * Impotence * menstrual irregularities * **hirsutism** (abnormal hair growth) * **deepening voice**

What are drug interactions of K+ sparing diuretics, Spironolactone?

* DO NOT give w/ drugs increasing plasma potassium * use cautiously w/ ACE (-) in heart failure * combined w/ thiazides & loop diuretics to counteract their potassium loss

What are the therapeutic uses of Spironolactone?

K+ sparing diuretic (aldosterone antagonist) * **Primary hyperaldosteronism** * **severe heart failure (anti-fibrotic agent)** * Combined with K+ losing diuretics to counteract potassium loss

What is the MOA of aquaretics? What’s the goal of their use?

-vaptans (Conivaptan, Tolvaptan) **Increase free water clearance by selective V2 receptor antagonism** the purpose being to correct for a proper Na+:free water

What is a major consideration with the _oral administration_ of aquaretics such as Tolvaptan?

can cause **hyponatremia** and should be used for **less than 30 days** or the patient runs the risk of developing **hepatotoxicity**

**Non-peptide** arginine vasopressin receptor antagonists w/ affinity for receptor subtype V1A and V2

Aquaretics: **Conivaptan, Tolvaptan**

Which aquaretic is given orally and which is administered by IV?

Tolvaptan - oral Conivaptan - Intravenously

What are the clinical applications of Aquaretics (Conivaptan, Tolvaptan)

1. Euvolemic/hypervolemic **_hypo_**natremia (correcting Na+:free water) 2. slows progression of **adult polycystic kidney disease** (**must monitor liver**)

What is the typical dose for an osmotic diuretic (mannitol)?

**50-200 _grams_** over 24 hours

If you’re presented with a patient with: renal insufficiency, nephrotic syndrome, or severe congestive heart failure what is your first choice diuretic?

Loop diuretic (Furosemide) then add thiazide if you need to (these are acute patients that need to lose fluid fast)

What is a major difference between Spironolactone and Eplereonone?

Both K+ Sparing (Aldosterone antagonists) Eplerenone - **does not** cause gynecomastia Spironolactone - has been correlated w/ gynecomastia