Thiazide Diuretics


Thiazide Diuretics

  • JNC8 recommends Thiazides with ACE-I, ARBS, and CCBs
  • Thiazide diuretics are inexpensive effective agents for HTN
  • Thiazides cause hypokalemia which causes dig toxicity
  • Thiazides should be used with caution in patients with gout
  • Initially thiazides cause diuresis then it decreases PVR after long term usage
  • A patient may develop hyperglycemia after being prescribed a thiazide diuretic
  • Thiazide diuretics reduce calcium excretion by the kidneys and stimulate osteoblasts which help build bone
  • Should avoid in patients with serious sulfa allergies; Potassium sparing diuretics such as triamterene & amiloride are alternative options for these patients
  • Patients with HTN & osteoporosis have an extra benefit from thiazides



  • Uncomplicated HTN (1st line)
  • Heart Failure
  • Edema
  • HTN accompanied by osteoporosis


Side Effects

  • Hypokalemia
  • Hyperuricemia
  • Hypotension
  • Hypercalcemia
  • Electrolyte imbalance
  • Volume Depletion
  • Hypergylcemia
  • Hyperlipidemia



Drug Name Hydrochlorothiazide
-Assess for allergy to sulfa drugs
-Most common class of diuretics used
-Do not use in patients with gout
MOA-↓ BP by ↓ blood volume
-Acts mainly in the distal tubule to ↓ the reabsorbtion on NA+ ; inhibit reabsorption of Na+ and Cl- in the distal convoluted tubule
↓ SERUM Na+ concentration (hypernatremia)
Effects of Drug-↑ Excretion of Na+ & Cl- (Hyperosmolar urine)
-↑LOSS OF K+ due to the increase in Na+ in the filtrate arriving at the detail tubule
-↑ in exchange of K+ for Na+ (can result in hypokalemia)
-↑ loss of Mg+ can occur in elderly
-↓Urinary calcium excretion (↓Ca+ content of urine by promoting reabsorption of Ca+)
-Reduced peripheal
vascular resistance
-↓in BP results from a ↓ in blood volume = ↓CO
-↑Lipid levels
-↓Urate Excretion
Therapeutic Effects-HTN
-Heart Failure
-Diabetes Insipidus
-DOC for mild HTN & in elderly patients
-Combine with another drug for severe HTN
Side Effects-Idiosyncratic rxn (rash, photosensentivity, purpura)
-↑plasma renin
-Hyperuricemia (gout)
-Hypercalcemia (esp. hyperparathryroid pt)


Edmunds, M. W., & Mayhew, M. S. (2014). Pharmacology for the primary care provider (4th ed.). St. Louis, MO: Elsevier Mosby.

Harvey, R. A., Clark, M. A., Finkel, R., Rey, J. A., & Whalen, K. (2012). Pharmacology (5th ed.). Baltimore, MD: Lippincott.

JNC8 Guidlines 2014. (2014). JNC 8 Guidlines. Retreived from: