What is the mechanism of action of hydrochlorothiazide?

What is the mechanism of action of hydrochlorothiazide?

Mechanism of Action Hydrochlorothiazide inhibits sodium chloride transport in the distal convoluted tubule. More sodium is then excreted in the kidney with accompanying fluid. Pharmacological effects begin in about 2 hours after an oral dose, peak in 4 hours, and lasts for about 6 to 12 hours.

What is the mechanism of action for a diuretic?

They act by diminishing sodium reabsorption at different sites in the nephron, thereby increasing urinary sodium and water losses. A second class of diuretics, sometimes termed aquaretics, instead inhibit water reabsorption by blocking vasopressin receptors along the connecting tubule and collecting duct.

What is mechanism of action for diuretics treating hypertension?

The exact mechanism of antihypertensive action of diuretics is not known. All diuretics initially lower the blood pressure by increasing urinary sodium excretion and reducing plasma volume, extracellular fluid volume, and cardiac output.

How do thiazide and thiazides diuretics lower blood pressure?

Some of the most commonly prescribed antihypertensives, thiazide and thiazide-like diuretics are thought to chronically lower blood pressure primarily by reducing total peripheral resistance.

What are the pharmacokinetics of thiazide diuretics?

Pharmacokinetics of and Differences Among Thiazides Thiazides are readily absorbed and are extensively bound to plasma proteins. They are eliminated largely through secretion by the S2 segment of the proximal tubule, mostly via OAT1 and OAT3.

How does thiazide reduce blood pressure?

By decreasing sodium reabsorption, thiazide use acutely results in an increase in fluid loss to urine, which leads to decreased extracellular fluid (ECF) and plasma volume. This volume loss results in diminished venous return, increased renin release, reduced cardiac output and decreased blood pressure [7].

What is the primary target of thiazide diuretics?

The primary target of hydrochlorothiazide (and other thiazide/thiazide-like diuretics) is the sodium-chloride symporter (SLC12A3, NCC) on the apical membrane of the renal distal tubule. Hydrochlorothiazide is transported from the blood to its site of action by the renal proximal tubule organic acid secretory pathway.

How do thiazides and loop diuretics differ in their mechanisms of action?

Thiazides decrease the urinary excretion of calcium, while loop-diuretics have the opposite effect. The possibility of loop-diuretic induced osteopenia cannot be ruled out, which should be considered when choosing between thiazides and loop-diuretics for the treatment of mild to moderate CHF.

How do thiazide diuretics treat hypertension?

Thiazide diuretics are used to treat high blood pressure by reducing the amount of sodium and water in the body. Thiazides are the only type of diuretic that dilates (widens) the blood vessels, which also helps to lower blood pressure.

Which thiazide is used for hypertension?

Chlorthalidone and indapamide, both thiazide-like diuretics, have been shown to provide greater antihypertensive efficacy and, more importantly, to reduce cardiovascular events and mortality compared with hydrochlorothiazide (a thiazide-type diuretic) [1].

What is a potential effect of thiazide diuretics?

Side effects include increased urination and sodium loss. Diuretics can also affect blood potassium levels. If you take a thiazide diuretic, your potassium level can drop too low (hypokalemia), which can cause life-threatening problems with your heartbeat.

What is the site of action of chlorothiazide?

As a diuretic, chlorothiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water.

How does thiazide cause vasodilation?

The main conclusions of the present study are that hydrochlorothiazide exerts a direct vasodilator effect in the human forearm at supratherapeutic plasma levels and that this action is mediated by activation of vascular potassium channels and not by inhibition of a putative vascular Na-Cl cotransporter.

What is the difference between thiazide and loop diuretics?

What type of diuretic is thiazide?

What are Thiazide diuretics? Thiazide diuretics are a type of diuretic (a drug that increases urine flow). They act directly on the kidneys and promote diuresis (urine flow) by inhibiting the sodium/chloride cotransporter located in the distal convoluted tubule of a nephron (the functional unit of a kidney).

Why thiazides are preferred in hypertension?

For hypertensive patients with diabetes, the American Diabetes Association gives preference to thiazide-like diuretics (chlorthalidone and indapamide) because they are longer acting diuretics that have a proven effect on cardiovascular event reduction [45].

What is the effect of chlorothiazide?

Chlorothiazide is a thiazide diuretic (water pill). It reduces the amount of water in the body by increasing the flow of urine, which helps to lower blood pressure and remove excess fluid (edema). This medicine is available only with your doctor’s prescription.

What is the chemical name of chlorothiazide?

Chlorothiazide

Do thiazide diuretics dilate blood vessels?

1. Thiazide diuretics are used to treat high blood pressure by reducing the amount of sodium and water in the body. Thiazides are the only type of diuretic that dilates (widens) the blood vessels, which also helps to lower blood pressure.