E1. Diuretics Flashcards
What are the different classes of diuretics? (7)
- Cardiovascular diuretics
- Physiological diuretics
- Osmotic diuretics
- Loop or high ceiling diuretics
- Thiazide diuretics
- Potassium – sparing diuretics
- Carbonicanhydrase inhibitors
What is a diuretic?
Diuretic is a drug that increases the rate of urine flow. They are also able to increase the rate of sodium excretion (usually as sodium chloride).
The 2 major types of cardiovascular diuretics?
Digitalis (digoxin) Phosphodiesterase inhibitors – aminophylline – inamrinone –milrinone
A dog came into your clinic with edema associated with congestive heart failure, what drug(s) should you use? A.Sodium chloride B. Digitalis C. Digoxin D. B and C E. All of the above
D. B and C
What drugs are physiological diuretics? What can they be used in?
Water
– used to compensate chronic interstitial nephritis of dogs
Sodium chloride
– used in urolithiasis in sheep, calves and cats.
What drugs are osmotic diuretics?
Mannitol
Urea
Glycerin
Isosorbide
Where and how do osmotic diuretics work?
- They act in the loop of Henle which is the primary site and in the proximal tubule which is a secondary site.
- The may interview with transport mechanisms in the thick ascending limb and increasing the urinary excretion of sodium, potassium, calcium, magnesium, chloride, bicarb, and phosphate.
- It can also act by an osmotic effect medullary tenicity.
- They also increase renal blood flow and renal medullary blood flow by several mechanisms.
You have an animal with cerebral edema what class of diuretic should you use? A. Cardiovascular diuretics B. Physiological diuretics C. Osmotic diuretics D. Loop or high ceiling diuretics E.Thiazide diuretics
C.Osmotic diuretics
You have an animal with glaucoma what class of diuretic should you use? A. Physiological diuretics B. Cardiovascular diuretics C. Carbonic anhydrase inhibitors D. Potassium – sparing diuretics E. None of the above
E. None of the above
It should be osmotic diuretics.
You have an animal with acute renal failure, what class of diuretics should you use? A. Osmotic diuretics B. Thiazide diuretics C. Carbonic anhydrase inhibitors D. Potassium – sparing diuretics E. None of the above
A. Osmotic diuretics
What class of diuretics should be used to treat the mobilization of edema fluid and patients with drug overdose? A. Thiazide diuretics B. Osmotic diuretics C. Carbonic anhydrase inhibitors D. Potassium – sparing diuretics E. None of the above
B. Osmotic diuretics
What are the pharmacokinetics associated with osmotic diuretics? (3)
– Mannitol and urea are administered intravenously
– Glycerin and Isosorbide are administered orally
– mannitol is not metabolized and is eliminated rapidly by the kidneys
What are the drugs in your for high ceiling diuretic classifications? (3)
– Furosemide
–Bumetanide
–Ethacrynic
What are other names for furosemide? (2)
Lasix or Salix
What is the MOA of loop or high ceiling diuretics?
-It will inhibit the sodium potassium chloride symporter
Why are the loop diuretics considered to be the most efficacious diuretics?
Because approximately 25% filtered sodium is reabsorbed in the thick ascending loop.
When would you want to use a loop or high ceiling diuretic? (8)
– treatment of acute pulmonary edema and pulmonary congestion
– treatment of generalized edema associated with congestive heart failure, chronic renal failure and liver cirrhosis.
– combined with isotonic saline to treat hypercalcemia and to prevent volume depletion.
– may be useful in patients with acute renal failure.
– Treatment of increased intracranial pressure and udder.
– Drug overdose
– Combined with hypertonic saline for the treatment of life-threatening hyponatremia because loop diuretics inhibits the kidney from producing concentrated urine.
– it is effective in the treatment of edema of nephrotic syndrome which is usually refractory to other diuretics.
You have an horse that has exercise induced pulmonary hemorrhage, what drug(s) should you use? A. Glycerin B. Digoxin C. Lasix D. Furosemide E. Mannitol
D. Furosemide
C. Lasix
What are the adverse effects associated with loop or high ceiling diuretics? (10)
– Ototoxicity – hypokalemia – Hypomagnesium – acute hypovolemia – hypotension – cardiac arrhythmias – hyperglycemia – Hyperuricemia – systemic alkalosis – hypersensitivity reactions in patients allergic to sulfonamides
What is the pharmacokinetics of furosemide? (3)(administration, on set of action/duration, metabolism)
– Administered orally and intravenously
– onset of action is rapid and duration of action short
– Partly metabolized by conjugation and partly excreted unchanged in urine and is actively secreted urine by the organic acid secretory mechanism.
Name the thiazide diuretics. (2)
– Hydrochlorothiazide
– Chlorothiazide
What is the mechanism of action for the thiazide diuretics?
They inhibit the sodium Chloride symporters in the distal convoluted tubule resulting in inhibition of the tubular reabsorption of sodium, chloride and diuresis.
It also inhibits potassium and magnesium reabsorption, but increases reabsorption of calcium.
*Thiazide diuretics cause hypokalemia and systemic alkalosis by mechanisms similar to loop diuretics.
What are the therapeutic uses thiazide diuretics? (5) d
– Treatment of edema from CHF, liver cirrhosis, nephrotic syndrome, and acute glomerulonephritis
– 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.
What are the adverse effects of thiazide diuretics?(4)
–Electrolyte imbalances (hyponatremia, hypokalemia (big issue), hypomagnesemia) are less than with diuretics.
– Hyperglycemia.
– Hypersensitivity reactions in patients allergic to sulfonamides.
– Hyperlipidemia.
*Hypertension is a risk factor for cardiovascular disease animals.
