Thiazides (FETT)

Diuretics

BENDROFLUMETHIAZIDE

• Inhibition of Na+-Cl- cotransporters in the early distal convoluted tubule → ↑ excretion of Na+ (saluresis) and Cl- → ↓ diluting capacity of nephron and ↑ excretion of potassium (kaliuresis) and ↓ excretion of calcium → diuresis

• Increased reabsorption of Ca2+

• Hyperpolarization of smooth muscle cells → vasodilation

• Hyperpolarization of pancreatic beta cells → decreased insulin release [8]

• Hypokalemia and metabolic alkalosis

• Hyponatremia [10]

• Hypomagnesemia

• Hypercalcemia

• Hyperglycemia [11]

• Hyperlipidemia (↑ cholesterol, triglycerides)

• Hyperuricemia

• Allergic reactions (sulfonamide hypersensitivity)

—> To avoid hypokalemia, thiazide diuretics may be combined with potassium-sparing diuretics (e.g., aldosterone receptor antagonists).

To remember the side effects of thiazide diuretics, think of “hyperGLUC”: hyperGlycemia, hyperLipidemia, hyperUricemia, and hyperCalcemia.

• Hypertension

• Chronic edema secondary to congestive heart failure, cirrhosis, and kidney disease

• Prevention of calcium kidney stones, idiopathic hypercalciuria

• Osteoporosis

• Nephrogenic diabetes insipidus

• Sequential nephron blockade

• Hypersensitivity (including hypersensitivity to any sulfonamide medications)

• Gout

• Anuria

• Severe hypokalemia

Thiazides should be used with caution in patients with prediabetes and diabetes mellitus because they can cause hyperglycemia and changes in glucose concentration.

• Glucocorticoids: increased hypokalemia

• Carbamazepine: increased hyponatremia

• Lithium: increased hyponatremia

• ACE inhibitors: hypotension (especially first-dose hypotension)

• Propranolol: increased hyperlipidemia and hyperglycemia

• NSAIDs: decreased diuretic effect

• Increased effects of digitalis , methotrexate, and lithium