Diuretics Flashcards
Osmotic Diuretic Drugs
Mannitol
Urea
Glycerin
Isosorbide
Mechanism of Action of Osmotic Diuretics
Act in lop of henle (primary) and prox tubule (secondary)
May interfere w/ transport mechanisms of thick ascending limb increasing the urinary excretion of Na+, K+. Mg, Cl, HCo3 and phosphate
Therapeutic uses for Osmotic Diuretics
tx of: cerebral edema glacoma acute renal failure mobilization of edema fluid drug overdose
Pharmacokinetics of Osmotic Diuretics
Mannitol and Urea- IV
Glycerin and Isosorbide oral
Mannitol not metabolized and eliminated rapidly by kidneys
Loop/High Ceiling Diuretic Drug?
Furosemide
Cardiovascular Diuretics
Digitalis
Amniophylline
Theraputic use of Cardiovascular Diuretics
Tx of edema associated with CHF
Mechanism of action of Loop Diuretics
Inhibit NaK2Cl symporter at the luminal membrane in thick ascending limb in the loop of Henle. Inhibits paracellular reabsorbtion of Na, Ca and Mg.
Theraputic uses for Loop Diuretics
acute pulmonary edema and congestion
generalized edema associated with CHF, chronic renal failure, liver cirrhosis
Adverse effects of loop diuretics
ototoxicity hypokalemia hypomagnesemia acute hypovolemia hypotension cardiac arrhythmias hyperglycemia hyperuricemia systemic alkalosis
Pharmacokinetics of furosemide
Oral and IV
Onset rapid duration short
Partly metabolized by conjugation and partly excreted unchanged in urine and actively secreted in urine by the organic acid secretory mechanism
Thiazide Diuretic Drugs
Hydrochlorothiazide
Chlorothiazide
Mechanism of Action of Thiazide Diuretics
Inhibit NaCl symporter in distal convoluted tubule inhibitng tubular reabsorption of NaCl and diuresis
Therapeutic uses of Thiazide Diuretics
Tx of edema of CHF, liver cirrhosis, nephroitc syndrome, acute glomerular nephritis, hypertension, nephrogenic diabetes insipidus , Ca nephrolithiasis, osteoperosis, udder edema
Adverse affects of Thiazide Diuretics
Electrolyte imbalances (hypoNa, hypoK, hypoMg) Hyperglycemia
Pharmacokinetics of thiazide diuretics
oral
absorption slow and incomplete
bind extensively to plasma proteins
excreted mainly by the kidneys and actively secreted in urine
decreased renal blood flow decreases affect
Potassium Sparing Diuretics Drugs
Spironolactone
Triaamterene
Amiloride
Spiranolactone MoA
Competitively blocks aldosterone binding to aldosterone receptor in the late distal tubule and collecting duct.
Excretion of NaCl and diuresis, retention of K+ and H+
Therapeutic uses of Spironolactone
diuretic
tx of primary and secondary hyperaldosteronism
Adverse effects of Spironolactone
hyperkalemia
systemic acidosis
reproductive effects because it acts on progesterone and adrogen receptors
Pharmacokinetics of Spironolactone
oral
readily absorbed and highly bound to plasma proteins
extensively metabolized by the liver and converted to an active metabolite
onset slow duration long
Amiloride therapeutic uses
tx of hypokalemia and hypomagnesemia
occasionally used in edematous disorders and hypertension (very weak diuretics)
Amiloride adverse effects
hyperkalemia
systemic acidosis
Amiloride Pharmacokinetics
oral
Amiloride is excreted by kidneys
What are the Carbonic Anhydrase Inhibitor drugs?
Aetazolamide
Methazolamide
Dorzolamide, brinzolamine (opthalmic)
MoA for Carbonic Anhydrase Inhibitors
Reversible inhibition of carbonic anhydrase which inhibits the exchange of H for Na in the proximal tubule which is the primary site
A secondary site of CA is the collecting duct
CA inhibitors lower intraocular pressure
Therapeutic uses of Carbonic Anhydrase Inhibitors?
Tx of chronic glaucoma
acetazolamide has been used in udder edema
Adverse effects of CA inhibitors?
Mild systemic acidosis
hypokalemia
hyperglycemia
Dogs- v/d, hyperventilation, polyuria/polydipsia, behavioral changes, pruritis of paws
Phamacokinetics of CA inhibitors
Acetazolamide oral
onset 30 min, duration 4-6 hours in small animals
Acetazolamide is eliminated mainly by the kidneys and is actively secreted in urine by organic acid secretory mechanism
Dorzolamide topical on eye
