Diuretics Flashcards
which medication is a carbonic anhydrase inhibitor?
acetazolamide
which medications are loop diuretics?
Furosemide
bumetanide
which medications are thiazide diuretics?
- hydrochlorothiazide
- metolazone
which medications are potassium sparing diuretics?
Spironolactone
triamterene
medications that help the body get rid of sodium and water
- this decrease in fluid volume can improve your health (lower blood pressure, improve cardiovascular funtion, etc)
Diuretics
- appears to be dose dependent
- absorption is erratic with daily doses > 10mg/kg
- has a half life of about 2.5 to 6 hours
- excreted 70-100% as unchanged drug in the urine
Acetazolamide
what are uses of acetazolamide?
- altitude sickness
- metabolic alkalosis
- removing acidic drugs
- cerebral edema
- glaucoma
what are contraindications and adverse drug effects of acetazolamide?
contraindications of acetozolamide
- history of anaphylactic reactions to sufonamides
- severe renal/ hepatic dysfunction
Adverse drug effects:
- dizziness
- polyuria
- confusion, tachypnea, tachycardia
- nausea/vomiting
MOA: Blockade of NA+, K+, 2Cl- transporter in ascending limb of the loop of henle (more sodium Na+ in filtrate, more total volume removed in urine)
Loop diuretics
uses of loop diuretics? contraindications?
Uses (either IV or PO)
- CHF
- Nephrotic syndrome/ cirrhosis
- edema
- hypertension
- hyperkalemia/hypercalcemia treatment
Contraindications
- history of anaphylactic reactions to sulfonamides
- kidney failure
- pregnancy
Furosemide IV:PO conversion 1:2; bumetanide 40x more potent
adverse drug effects of loop diuretics?
- Depletion of Na+, Cl-, Mg+, and especially K+ (hypokalemia)
- ototoxicity (not generally permeant)
- furosemide should not exceed 4mg/min given iV
- exacerbation of gout/ hyperuricemia
- allergic interstitial nephritis
- hyperglycemia
- dyslipidemia
DI: NSAIDs, aminoglycosides, digoxin/QT prolonging drugs
MOA: inhibition of Na+/Cl- cotransporter (aka symporter)
Thiazide diuretics
uses and adverse drug effects of thiazide diuretics?
Uses
- edema/ fluid retention
- CHF
- hypertension
Adverse drug effects
- Hypokalemia
- hyperuricemia
- impotence
- glucose intolerance
- hypercholesterolemia
usually ineffective in CrCl < 30 unless used with loop diuretic (except metolazone due to its greater potency)
drug interactions and contraindications of thiazide diuretics?
Drug interactions
- first dose hypotension when ACE-I added
- NSAIDs
- lithium
- digoxin
Contraindications
- history of anyphylactic reactions to sulfonamides
- anuria
- blockade of aldosterone receptors in distal tube/collecting duct
- only group today that doesn’t act through tubular secretion
spironolactone
- blockade of sodium channel in distal tubule
- creates depolarization of luminal side of cell, results in potassium secretion into tubular lumen
Triamterene
uses and contraindications of potassium sparing diuretics?
uses/routes (PO)
- CHF: sprionolactone
- cirrhosis: sprionolactone
- primary aldosteronism: sprionolactone
- hypertension: Either
Contraindications
- hyperkalemia
- renal/ hepatic failure
adverse effects of potassium sparing diuretics?
All
- hyperkalemia
- metabolic acidosis
- dizziness
Trimaterene
- flatulence
- rash
- nephrolithiasis
Spironolactone
- steroid side effects
- gynecomastia
drug interactions of potassium sparing diuretics?
- ACE-I, potassium supplements
- NSAIDs
- hyperkalemia
consequences of hypokalemia?
- can worsen hepatic encephalopathy in liver dysfunction
- in patients with cardiac history, increased risk of arrhythmias even with mild hypokalemia
- hypertension
- muscle cramps, myalgia, weakness
Management
K+ = 3.5-4mEq - Diet
K+= 3-3.5mEq- initiate replacement in high risk pts
K+ < 3 mEQ: Replacement (alternative: add potassium sparing diuretic)
- alternative loop diuretic
- can be used in patient with severe allergies to other loop diuretics
- more expensive and more side effects including ototoxicity
Ethacrynic Acid
