Pharmacology Renal/Genitourinary Agents.
CHAPTER 32
Diuretics
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DRUG OVERVIEW
- Diuretics
Thiazides and thiazide-like inhibitors
Sodium channel blockers
Loop Diuretics
Carbonic anhydrase inhibitors
Potassium-sparing
Sodium channel blockers
Aldosterone antagonists
- Fixed-dose combination therapies
HCTZ with amiloride, spironolactone, or triamterene
- Potassium supplements
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Facilitate Loss of sodium and water
Reduce Cardiac Output and blood pressure
After usually 8 weeks return to normal (CO)
BP remains reduced
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INDICATIONS
- Hypertension
- Congestive heart failure
- Renal failure
- Cirrhosis
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THIAZIDE DIURETICS: MECHANISM OF ACTION
5%-7% of filtered Na is reabsorbed
Inhibit sodium reabsorption in the distal tubule through inhibition of NaCl transporter
Effect blunted by reabsorption of sodium distally in cortical collecting tubule
Less efficacious for edema
During long-term therapy for HTN, may decrease peripheral vascular resistance
Enhance calcium absorption and lessen excretion
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Used as initial therapy, either alone or in combo with ACE inhibitors ARB B blockers or Calcium channel blocers
MOA: Inhibit sodium reabsorption in the distal tubules causing increased excretion of sodium and water, potassium and hydrogen ions
Adverse effects: Potassium depletion, mag, hyponatremia, hyperglycemia, increase serum lipid concentrations, precipitate gout
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LOOP DIURETICS: MECHANISM OF ACTION
20% of filtered Na is reabsorbed
Inhibit reabsorption of sodium and chloride in ascending loop of Henle and distal renal tubule and cause increased excretion of water, sodium, chloride, magnesium and calcium
Promote excretion of calcium: Clinically relevant effect
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