Diuretics Flashcards Preview

RUSVM Pharmacology > Diuretics > Flashcards

Flashcards in Diuretics Deck (50)
Loading flashcards...
1

Classes of Diuretics

Cardiovascular Diuretics

Physiological Diuretics

Osmotic Diuretics

Loop (High Ceiling) Diuretics

Thiazide Diuretics

Potassium Sparing Diuretics

Carbonic Anhydrase Inhibitors

2

Physiologic Diuretics

Not diuretic by definition, but have diuretic effect

3

Major effects of Alpha 1 adrenoceptors

Vasoconstriction

Increased peripheral resistance

Increased blood pressure

Mydrasis

Increased closure of internal sphincter of the bladder

4

Therapeutic uses of osmotic diuretics

Treatment of cerebral edema

Treatment of glaucoma

Treatment of acute renal failure

Mobilization of edema fluid

Used in patients with drug overdose

5

Examples of Carbonic Anhydrase Inhibitors

Acetazolamide

Methazolamide

Dorzolamide and Brinzolamide (Topical Ophthalmic)

6

Adverse effects of Thiazide diuretics

Electrolyte imbalances

Hyperglycemia

Hypersensitivity reactions

Hyperlipidema

7

Most effective diuretics are

Loop diuretics

________________________________

Inhibit the most reabsorption of Na acting on ALoH

8

Diuretic efficacy of Spironolactone depends on

Levels of endogenous aldosterone

9

Pharmacokinetics of Triamterine and Amiloride

Admistered orally

Amiloride is excreted by the kidneys

Triamterene is convered to an active metabolite in the liver whihc is actively secreted in the urine

10

What osmotic diuretic is not metabolized and is elimiated rapidly by the kidney

Mannitol

11

Pharmacokinetics of Thiazide Diuretics

 

Administered orally

Absorption is slow and incomplete

Bind extensively to plasma proteins

Excreted maily by the kidneys and are actively secreted in urine by the organic acid secretory machanism

Decreased renal blood flow decreases their effectiveness

12

Glycerin and isosorbide are administered

Orally

13

Pharmacokinetics of Spironolactone

Administered orally

Readily absorbed and is highly bound to plasma protein

Extensively metabolized by the liver and is converted to an active metabolite

Onset of action is slow (2-3 days) and duration of action is long

14

Diuretic

Medication that increases urine flow or urine volume

15

T/F: Diuretics are drugs that increase urination

False

16

Potency of diuretics depends on

Where it acts in the nephron

17

Examples of physiologic diuretics

Water

Sodium Chloride

18

Therapeutic uses of Thiazide Diuretics

Treatment of edema of CHF, liver cirrhosis, nephrotic syndrome and acute glomerular nephritis

Treatment of hypertension alone or combined with other antihypertensive drugs

Treatment of nephrogenic diabetes insipidus and useful in central diabetes insipidus

Treatment of calcium nephrolithiasis and may be useful for the treatment of osteoporosis

Treatment of udder edema in cows

19

Duretics ranked from most effect to least effective

Loop Diuretics > Thiazide Diuretics > Osmotic Diuretics > Potassium Sparing Diuretics

20

Adverse effects of carbonic anhydrase inhibitors

Mild systemic acidosis

Hypokalemia

Hyperglycemia

 

21

Mechanism of Action of Osmotic Diuretics

  1. Interfere with transport mechanisms in the thick ascending limb increasing the urinary excretion of Na, K, Ca, Mg, Cl, HCO3 and phosphate
  2. Osmotic effect in the tubule and reduce medullary tonicity
  3. Increase renal blood flow and renal medullary blood flow by several mechanisms

22

Mechanism of action of Loop or Ceiling Diuretics 

  1. Inhibit Na-K-Cl Symporter in the loop of henle
  2. Inhibits the paracellular reabsorption of Na, Ca, Mg
  3. Increased Na delivery to late distal tubule and collecting duct increases depolarization of the luminal membrane creating a lumen -negative transmembrane potentail difference - facilitates K excretion
  4. Stimulate Renin-Angiotension- Aldosterone
  5. Increases total renal blood flow
  6. Increase systemic venous capacitance

23

Therapeutic uses of Triamterine and Amiloride

Treatment of hypokalemia and hypomagnesemia

Occassionally used in edematous disorders and hypertension - very weak diuretics

24

Mannitol and urea are administered 

IV

25

Mechanism of action of Spironolactone

  1. Competitively blocks aldosterone binding to aldosterone receptor in the late distal tubule and collecting duct
  2. Excretion of NaCl and diuresis as well as retention of K and H

26

Major effects of Alpha 2 adrenoceptors

Inhibition of norepinephrine release

Inhibition of insulin release

27

Mechanism of Action of Thiazide Diuretics

  1. Inhibit the Na-Cl symporter in distal convoluted tubule - inhibition of tubular reabsorption of Na, Cl and diuresis
  2. Inhibit K and Mg reabsorption but increase reabsorption of Ca
  3. Cause hypokalemia and systemic alkalosis similarly to loop diuretics

28

Examples of Loop or Ceiling Diuretics

29

Therapeutic uses of Spironolactone

Diuretic

Treatment of primary and secondary hyperaldosteronism

30

Adverse effects of loop or ceiling diuretics

Ototoxicity

Hypokalemia

Hypomagnesemia

Acute hypovolemia

Hypotension

Cardiact arrhythmias

Hyperglycemia

Hyperuricemia

Systemic alkalosis

Hypersensitivity reactions