Diuretics

Question 1

Broad Categories of Diuretics

Answer 1

• Carbonic Anhydrase Inhibitors: acetazolamide
• Loop diuretics: furosemide
• Osmotic diuretics: mannitol
• Potassium-sparing diuretics: spironolactone
• Thiazides: hydrochlorothiazide

Question 2

Carbonic Anhydrase Inhibitors

Answer 2

Work in the Kidneys; Note on MOA: if you don’t have enough H+ to exchange for Na+, you’ll lose Na+ and H2O and Cl- in urine

• MOA: Dec. H+ formation
• Indications: glaucoma & edema
• Contraindications: Allergy, hyponatremia, hypokalemia (because this drug works on part of kidneys where all major electrolytes are being effected), hepatic or renal dysfunction, sensitivity to sulfonamide antibiotics, diabetes.
• Adverse Effects: METABOLIC ABNORMALITIES, Drowsiness, Anorexia, paresthesias, hematuria, melena, hyperglycemia
• Interactions: Digoxin, Corticosteroids, Amphetamines, carbamazepine, cyclosporine, phenytoin & quinidine
• Nursing Considerations:

Question 3

Loop diuretics

Answer 3

Produce PROFOUND fluid loss so will see electrolyte changes across the board.

• MOA: Blocks chloride and sodium resorption
• Indication: Heart Failure, renal failure, liver failure and Hypertension
• Contraindications: Allergy, allergy to sulfonamide antibiotics, hepatic coma, severe electrolyte imbalances,
• AE: Dizziness, headache, tinnitus, ototoxicity (especially when parenteral forms are administered too quickly), and electrolyte disturbances (especially K+ loss!)
• Interactions: ibuprofen, digoxin

Question 4

Osmotic Diuretics

Answer 4

Osmotic diuresis is the increase of urination rate caused by the presence of certain substances in the small tubes of the kidneys. The excretion occurs when substances such as glucose enter the kidney tubules and cannot be reabsorbed (due to a pathological state or the normal nature of the substance).

• MOA: Proximal convoluted tubule and the descending loop of Henle—diuresis.
• Indications: Early, oliguric phase of ARF (as long as renal perfusion is adequate).
• Contraindications severe renal disease & pulmonary edema
• AE: Convulsions, pulmonary congestion, and thrombophlebitis at the site of injections.
• No significant interactions

Question 5

K+ Sparing Diuretics

Answer 5

• MOA: binding to aldosterone receptors and blocking resportion of sodium and water.
• Indications: Hyperaldosteronism, HTN, counteract electrolyte loss among those taking potassium-wasting diuretics, and CHF
• Contraindications: hyperkalemia, severe renal failure,
• AE: Gynecomastia (large mammory glands: AKA, breasts) in men and dysmenorrhea in women, HYPERKALEMIA!
• Interactions: Lithium, NSAIDS, K+ supplements!

Question 6

Thiazides

Answer 6

Not as profound fluid loss as loop diuretics, but more effective because pt can still preform ADLs

• *FIRST LINE DRUG - along with amlodipine
• MOA: distal convoluted tubule—Diuresis
• Indications: Edema, HTN, and HF
• Contradictions: hepatic coma
• AE: Electrolyte disturbances, dehydration, orthostatic hypotension, impotence, and decreased libido
• Interactions: NSAIDS, Lithium, digoxin, Table 28-6; also monitor for HYPERGLYCEMIA