Diuretics

Thiazide Diuretics

• Mechanism of action
  • Inhibit sodium reabsorption at the beginning of the DCT by blocking thiazide sensitive $\mathrm{Na}{}^{+}-\mathrm{Cl}{}^{-}$ symporter
  • Increased sodium delivery to the DCT promotes excretion of potassium
  • When used in lower doses for hypertension, thiazides lower BP mostly by a vasodilator effect
• Indications
  • Hypertension
  • Oedema associated with heart failure or hepatic cirrhosis
  • Nephrogenic diabetes insipidus
• Adverse effects
  • Dehydration and postural hypotension
  • Hypokalaemia
  • Hyponatraemia
    • May precipitate heart failure with significant oedema at higher doses in conjunction with salt-restricted diet and/or potassium-sparing diuretics
  • Hypercalcaemia
    • Also causes hypocalciuria which decreases incidence of stones
  • Gout
    • Secondary to diuretic-induced hyperuricaemia typically at higher doses
    • Measure serum urate levels every 2-5 weeks and adjust dose of urate-lowering drugs if necessary
  • Impaired glucose tolerance
  • Pregnancy

Acetazolamide

Sources

• Passmedicine: Thiazide and thiazide like diuretics
• AMH Online: Thiazide and related diuretics