Thiazides Flashcards
What is the mechanism of action of thiazide diuretics?
Thiazide diuretics inhibit the sodium-chloride symporter in the distal convoluted tubule, leading to increased sodium, chloride, and water excretion.
What are common thiazide diuretics?
Hydrochlorothiazide, chlorthalidone, indapamide, and metolazone.
What are the primary indications for thiazide diuretics?
Hypertension, heart failure (mild cases), nephrolithiasis (calcium stones), and nephrogenic diabetes insipidus.
What electrolyte imbalances are associated with thiazide diuretics?
Hyponatremia, hypokalemia, hypomagnesemia, and hypercalcemia.
What metabolic disturbances are caused by thiazide diuretics?
Hyperglycemia, hyperlipidemia, and hyperuricemia (may precipitate gout).
Why do thiazide diuretics cause hypercalcemia?
Thiazides reduce calcium excretion in the distal convoluted tubule by increasing calcium reabsorption. This may be beneficial for osteoporosis.
In which conditions are thiazide diuretics contraindicated?
Anuria, hypersensitivity to sulfonamides, and caution in gout or severe renal impairment.
What drugs can exacerbate electrolyte imbalances when combined with thiazides?
Loop diuretics, corticosteroids, and amphotericin B (increased risk of hypokalemia and hypomagnesemia).
Which drugs can reduce the efficacy of thiazide diuretics?
Nonsteroidal anti-inflammatory drugs (NSAIDs).
If a patient has bipolar disorder, why should they not take thiazides?
Lithium toxicity.
Why is chlorthalidone preferred over hydrochlorothiazide for hypertension?
Chlorthalidone has a longer half-life and greater efficacy in lowering blood pressure.
What is a unique indication for thiazide diuretics unrelated to fluid balance?
Thiazides are used to treat nephrogenic diabetes insipidus by reducing polyuria.
What should be monitored during thiazide diuretic therapy?
Electrolytes (e.g., sodium, potassium, magnesium), renal function, and glucose levels in diabetics.
Why are thiazides beneficial for calcium stone nephrolithiasis?
They reduce urinary calcium excretion, decreasing the risk of calcium stone formation.
True or false: thiazide diuretics can help mitigate osteoporosis.
True.
True or false: thiazide diuretics can be used to treat renal tubular acidosis.
True.
