II. Indications: Potassium-Sparing Diuretics only (Aldosterone independent, Amiloride and Triamterene)
III. Indications: Aldosterone Antagonists (Spironolactone, Eplerenone)
-
Congestive Heart Failure
- Counter Aldosterone adverse effects on myocardial remodeling
IV. Mechanism
- Weak Diuretics (compared with Loop Diuretics or Thiazide Diuretics)
- Potassium-Sparing Diuretics only
- Primarily used to counter urinary Potassium loss with other Diuretics
- Act directly at the distal convoluted tubule (Aldosterone independent)
-
Aldosterone Antagonists (Spironolactone and Eplerenone)
- Commonly used as adjunctive in Congestive Heart Failure management
- Counter Aldosterone adverse effects on myocardial remodeling
V. Preparations: Potassium-Sparing Diuretics only (Aldosterone independent)
- Amiloride (Midamor)
- Dose: 5 mg orally daily (maximum: 20 mg/day)
- Renal excretion (unchanged in urine)
- Half-Life: 6 hours
- Triamterene (Dyrenium)
- Dose: 100 mg orally twice daily (maximum: 300 mg/day)
- Typically used as Combination Medication with Thiazide Diuretic
- Rapidly absorbed, highly metabolized in liver and Kidney and rapidly excreted
VI. Preparations: Potassium-Sparing Diuretic and Aldosterone Antagonists
VII. Precautions
- Monitor Serum Potassium after starting a Potassium-Sparing Diuretic in those at Hyperkalemia risk
- Obtain Serum Potassium at 3 days, 7 days and then monthly for the first 3 months
VIII. Adverse Effects: Potassium-Sparing Diuretics (Amiloride and Triamterene)
-
Hyperkalemia
- Risk factors
- Renal Insufficiency
- Concurrent use with agents that raise Potassium (e.g. ACE Inhibitors, Potassium supplements)
- Risk factors
- Blue Urine Color
- Specific to Triamterene
- Decreased renal perfusion (if Sodium and water depletion)
-
Glucose Intolerance
- Potassium-Sparing Diuretics
IX. Drug Interactions
- Potassium supplements (risk of Hyperkalemia)
X. References
- Olson (2020) Clinical Pharmacology, Medmaster, Miami, p. 62-3
- Hamilton (2010) Tarason Pocket Pharmacopeia, p. 100
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Related Studies
amiloride (on 7/20/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
AMILORIDE HCL 5 MG TABLET | Generic | $0.15 each |
AMILORIDE HCL-HYDROCHLOROTHIAZIDE 5-50 MG TAB | Generic | $0.43 each |
triamterene (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
TRIAMTERENE-HYDROCHLOROTHIAZIDE 37.5-25 MG CP | Generic | $0.12 each |
TRIAMTERENE-HYDROCHLOROTHIAZIDE 37.5-25 MG TB | Generic | $0.09 each |
TRIAMTERENE-HYDROCHLOROTHIAZIDE 75-50 MG TAB | Generic | $0.13 each |