Diuretics Lecture PDF Flashcards
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Diuretics function and major applications (2)
Increase output of urine
- treat hypertesnion
- mobilize edematous fluid
Diuretics mechanism of action
Blockage of Na+ and Cl- reabsorption, which prevents the passive reabsorption of water and causing water and solutes to be retained in the nephron promoting their excretion
Drugs whose site of action is early in the nephron have….
As a result they…
…opportunity to block greatest amount of solute reabsorption, produce greatest amount of diuresis
Loop diuretics work at the…
They are the most…
…ascending loop of henle, the most effective diuretics available
K+ sparing diuretics work at the…
They are very ___ diuretics because they don’t cause much ____, but can be helpful to reduce ____
…distal convoluted tuble and collecting duct
weak, diuresis, hypokalemia?
Furosemide (Lasix) mech of action, where is it excreted?
acts at thick ascending limb of loop of henle blocking reabsorption of Na+ and Cl-, preventing passive reabsorption of water
The liver excretes it
Loop diuretics have activity even during…
…renal failure
Furosemide (Lasix) length of action for oral and IV
Oral - diuresis lasts 8 hours after 1 hour absorption
IV, diuresis lasts for 2 hours within minutes
Furosemide (Lasix) therapeutic uses (3)
- reserved for rapid mobilization of fluid such as pulmonary edema with congestive heart failure
- uncontrolled hypertension
- Electrolyte imbalances
Furosemide (Lasix) ADR’s (7)
- Dehydration
- Thrombosis or embolism
- hypotension
- ototoxicity
- hyperglycemia
- hyperuremia (gouty attack)
- hyperlipidemia
Furosemide (Lasix) can be administered ___ to minimize unfavorable effects
Intermittent schedule
Furosemide (Lasix) drug interactions (3)
- Digoxin effects can be potentiated by loss of K+
- used in combo with aminoglycoside can increase hearing damage
- K+ sparing diuretics can counterbalance K+ wasting effects therby reducing risks of hypokalemia
Furosemide (Lasix) dosage oral, why is taking it in morning important
20 to 80mg/day single dose, administration at night will result in urination all night long
Hydrochlorothiazide (hydrouracil) drug class, mehc of action
Thiazide diuretic,
Blocks reabsoroption of sodium and chloride in early segment of distal convoluted tuble
Hydrochlorothiazide (hydrouracil) requires ___ to function, unlike ____
Adequate GFR, loop diuretics which can promote fluid loss with significant renal impairment
Hydrochlorothiazide (hydrouracil) indications (what is it the DOC for?) (4)
- HTN DOC
- Edema
- diabetes insipidus
Hydrochlorothiazide (hydrouracil) ADR’s (4)
- hypokalemia
- hyperglycmia
- hyperlipidemia
- produces fetal harm and shouldn’t be used during pregnancy
Hydrochlorothiazide (hydrouracil) is often avaiable with….
Fixed dose combo with K+ sparing diuretics
Hydrochlorothiazide (hydrouracil) oral administration dosage
25-50 mg, in the morning!
Non-thiazides defnition
Chemically different drugs that have similar function to thiazides
2 useful responses of K+ sparing diuretics
1) moderately increase urine production
2) substantial decrease in potassium excretion
Spironolactone (aldactone) mech of action, drug class
Blocks action of aldosterone at distal tubule, retention of K+and increased excretion of Na+,
K+ sparing diuretic
Spironolactone (aldactone) may take up to ___ to exert effects
48 hrs
Spironolactone (aldactone) indications (5)
- hypertension
- edema
- hepatic cirrhosis
- heart failure
- primary aldosteronism
Spironolactone (aldactone) ADR’s (2)
- hyperkalemia (never combine with K+ supplements or other K+ diuretics
- endocrine effects similar to other steroid hormones
Elperenone (Inspra) vs Spironolactone (aldactone)
Acts like spironolactone, K+ sparing diuretic but has lower affinity for andorgen receptors removing endocrine effects
Elperenone (Inspra) ADR
hyperkalemia
Triamterene (dyrenium) mech of action, drug class
Dirsupts Na/K ATPase exchange in distal nephron, a direct inhibitor acting very quickly but only producing minimal diuresis
-K+ sparing diuretic
Triamterene (dyrenium) therapeutic uses (2)
-used alone or incombo to treat hypertension and edema
Osmotic diuretic compound used in medicine
-mannitol (used in medicine)
Mannitol (osmitrol) mech of action and drug class
- pharmacologically inert
- creates osmotic force within lumen of nephron,
Osmotic diuretic
Mannitol (osmitrol) administration
IV injection
Mannitol (osmitrol) therapuetic uses (3)
- prophylaxis of renal failure
- reduciton of inracranial pressure
- reducjtion intraocular pressure
Mannitol (osmitrol) ADR’s (2)
- edema by pulling water into interstitial spaces
- can precipiptate congestive heart failure
Carbonic anhydrase inhibitors (acetazolamide (diamox)) function
Sulfonamide without antibacterial activity, primarily used for other pharmacologic actions such as treatment of glaucoma rather than diuretic effect because much less effacious than thiazides or loop diuretics
acetazolamide (diamox)) mehc of action
- Inhibitss carbonic anhydrase located intracelluarly on apical membrane of proximal convoluted tubular epithelium
- HCO3- is retained in lumen resulting in marked elevation of urinary pH - loss of HCO3- causes hyperchloremic metabolic acidosis and decreased diuretic efficacy after several days of therapy
acetazolamide (diamox) therapeutic uses (3)
- Glaucoma
- mountain sickness
- edema rarely used
acetazolamide (diamox) ADR’s (4)
- metabolic acidosis
- hypokalemia
- renal stone formation
- drowsiness and parasthesias
(T/F) Loop diuretics can be used with caution in pregnancy
true
Hydrochlorothiazide (hydrouracil) drug interactions (3)
- digoxin
- antihypertensive drugs
- lithium
