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Thiazide Diuretic

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Thiazide Diuretic, Thiazide, Hydrochlorothiazide, Chlorothiazide, Chlorthalidone, Indapamide, Metolazone, Zaroxolyn

  • Indications
  1. Hypertension (first-line agent)
  2. Osteoporosis Prevention (investigational)
  3. Severe Congestive Heart Failure
    1. Adjunct to Loop Diuretics
  4. Meniere's Disease
  • Contraindications
  1. Hyponatremia
    1. Do not use Thiazide Diuretics in patients with a history of Hyponatremia
  1. Thiazide Diuretics are minimally effective when GFR falls below 30 ml/min
  2. Switch to Loop Diuretics at this level of Renal Insufficiency
  • Adverse effects
  1. Hyperuricemia
    1. Occurs more often with doses over 25mg
    2. Less of an issue if avoid Hypokalemia
    3. Avoid Thiazide Diuretics in gout!
  2. Hyperglycemia
  3. Hyperlipidemia
  4. Hypokalemia
    1. One banana a day is sufficient Potassium Replacement
      1. Each inch of banana supplies 1 meq of Potassium
    2. Cost benefit is lost when Potassium supplement used
  5. Hyponatremia
  6. Hypomagnesemia
  • Preparations
  1. Hydrochlorothiazide (Esidrex, HydroDIURIL)
    1. Hypertension: 12 to 25 mg orally daily
  2. Hydrochlorothiazide and Triamterene
    1. Hctz/Triamterene 25/50 (Dyazide) one daily
    2. Hctz/Triamterene 50/75 (Maxzide) one daily
  3. Chlorothiazide (Diuril)
    1. Hypertension: 125-250 orally daily or divided bid
  4. Indapamide (Lozol)
    1. Hypertension: 1.25 to 5 mg orally daily
  5. Metolazone (Zaroxolyn)
    1. Hypertension: 0.5 mg orally daily (max: 1 mg daily)
    2. CHF with edema: 2.5 mg daily (max: 20 mg/day)
  6. Chlorthalidone (Hygroton)
    1. Hypertension: 12.5 to 25 mg orally daily
    2. May be preferred over Hydrochlorothiazide
      1. Longer half life than Hydrochlorothiazide
      2. Two to three times as potent as Hydrochlorothiazide
      3. Conversion: Use 12.5 mg of Chlorthalidone in place of 25 mg Hydrochlorothiazide
    3. Monitor Serum Potassium at baseline, 2 weeks and every 6-12 months (increased Hypokalemia risk)
      1. Decrease Sodium intake
        1. High Sodium intake is associated with increased Potassium losses
        2. Also associated with worse Blood Pressure control)
      2. Consider Potassium Supplementation
        1. Avoid if on Potassium sparing agents or significant Chronic Kidney Disease
        2. Potassium chloride 20 meq orally daily for Hypokalemia or prevention of Hypokalemia or
        3. Dietary Potassium for prevention of Hypokalemia
      3. Consider using Chlorthalidone in combination with agents balance Potassium losses
        1. Additional Blood Pressure lowering required
          1. ACE Inhibitor or Angiotensin Receptor Blocker
          2. Spironolactone or Eplerenone
        2. No additional Blood Pressure lowering required
          1. Triamterene or Amiloride
    4. References
      1. (2012) Presc Lett 19(2): 8
      2. (2014) Presc Lett 21(9): 52