]> 2013-05-18T12:31:12-07:00 Cyclothiazide taken from DrugBank http://www.drugbank.ca/drugs/DB00606 As a diuretic, cyclothiazide 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. Thiazides like cyclothiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of cyclothiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. Cyclothiazide is indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy. It is also indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effectiveness of other antihypertensive drugs in the more severe forms of hypertension. Pharmacology: Like other thiazides, cyclothiazide promotes water loss from the body (diuretics). It inhibits Na+/Cl- reabsorption from the distal convoluted tubules in the kidneys. Thiazides also cause loss of potassium and an increase in serum uric acid. Thiazides are often used to treat hypertension, but their hypotensive effects are not necessarily due to their diuretic activity. Thiazides have been shown to prevent hypertension-related morbidity and mortality although the mechanism is not fully understood. Thiazides cause vasodilation by activating calcium-activated potassium channels (large conductance) in vascular smooth muscles and inhibiting various carbonic anhydrases in vascular tissue. Cyclothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosages, all thiazides are approximately equal in their diuretic efficacy. Cyclothiazide increases excretion of sodium and chloride in approximately equivalent amounts. Natriuresis may be accompanied by some loss of potassium and bicarbonate. Mechanism of action: As a diuretic, cyclothiazide 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. Thiazides like cyclothiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. This results in an increase in potassium excretion via the sodium-potassium exchange mechanism. The antihypertensive mechanism of cyclothiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle or through its action on the large-conductance calcium-activated potassium (KCa) channel, also found in the smooth muscle. Drug type: Approved. Small Molecule. Drug category: Antihypertensive Agents. Diuretics DB00606 Cyclothiazide 2010-02-04T00:00:00 Molecule Ciclotiazida (INN-Spanish) Ciclotiazide (DCIT) Cyclothiazidum (INN-Latin) Anhydron Aquirel Doburil Fluidil Renazide Valmiran Molecule Synonym SuperCategory Glutamate receptor 2 Calcium-activated potassium channel subunit alpha 1 Carbonic anhydrase 4 Carbonic anhydrase 2 Carbonic anhydrase 1 Sodium/potassium-transporting ATPase gamma chain RelatedTo ModifiedDate Label Id Drug Has role Definition DefiningCitation Ab Curator Comment