Thiazide

Thiazide (/ˈθaɪəzaɪd/) refers to both a class of sulfur-containing organic molecules and a class of diuretics based on the chemical structure of benzothiadiazine. The thiazide drug class was discovered and developed at Merck and Co. in the 1950s. The first approved drug of this class, chlorothiazide, was marketed under the trade name Diuril beginning in 1958. In most countries, thiazides are the least expensive antihypertensive drugs available.Threshold Thiazide (/ˈθaɪəzaɪd/) refers to both a class of sulfur-containing organic molecules and a class of diuretics based on the chemical structure of benzothiadiazine. The thiazide drug class was discovered and developed at Merck and Co. in the 1950s. The first approved drug of this class, chlorothiazide, was marketed under the trade name Diuril beginning in 1958. In most countries, thiazides are the least expensive antihypertensive drugs available. Thiazide organic molecules are bi-cyclic structures that contain adjacent sulfur and nitrogen atoms on one ring. Confusion sometimes occurs because thiazide-like diuretics such as indapamide are referred to as 'thiazides.' These molecules do not have the thiazide chemical structure. When used this way, 'thiazide' refers to a drug which acts at the thiazide receptor. The thiazide receptor is a sodium-chloride transporter that pulls NaCl from the lumen in the distal convoluted tubule. Thiazide diuretics cause the body to release NaCl and water lumen, and increase the amount of urine made each day. An example of a molecule that is chemically a thiazide but is not used as a diuretic is methylchloroisothiazolinone. Methylchloroisothiazolinone is used as an antimicrobial in cosmetics. Thiazide diuretics are primary used to treat the hypertension (high blood pressure) and edema (swelling) caused by water overload as well as certain conditions related to unbalanced calcium metabolism. There are many causes of hypertension (high blood pressure), including advancing age, smoking and obesity. Sometimes the underlying cause of hypertension can not be determined, resulting in a diagnosis of idiopathic hypertension. Regardless of the cause, someone may have very high hypertension without any initial symptoms. Uncontrolled hypertension will eventually cause damage the heart, kidneys and eyes. Life style changes, including reducing dietary salt, increasing exercise and losing weight can help to reduce blood pressure. Thiazides and thiazide-like diuretics have been in constant use since their introduction in 1958. Decades as a cornerstone of hypertension treatment show how well these drugs preform for most patients. Low-dose thiazides are tolerated as well as the other classes of diuretics, including ACE inhibitors, beta blockers and calcium channel blockers. In general, the thiazides and thiazide-like diuretics reduce the risk of death, stroke, heart attack, and heart failure due to hypertension. Clinical practice guidelines regarding the use of thiazides varies by geographic region. Guidelines in the United States recommend thiazides as a first-line treatment for hypertension (JNC VIII). A systematic review by the Cochrane Collaboration specifically recommended that low-dose thiazides be used as the initial pharmacological therapy for high blood pressure. Low-dose thiazides are more effective at treating hypertension than beta blockers and are similar to angiotensin-converting enzyme (ACE) inhibitors. Also, thiazides are preferred because they are less expensive than low-dose thiazides. Thiazides are a recommended treatment for hypertension in Europe (ESC/ESH). However, the UK National Institute for Health and Clinical Excellence recommends ACE inhibitor and calcium channel blockers for first-line treatment of hypertension in adults (CG127). Thiazides should be considered as initial treatment if the patient has a high risk of developing heart failure. Thiazides have also been replaced by ACE inhibitors in Australia due to the association between thaizide use and increased risk of developing diabetes mellitus type 2. Thiazides can be used to paradoxically decrease urine flow in people with nephrogenic diabetes insipidus. Thiazides may also be useful in treating hyponatremia (low blood sodium) in infants with central diabetes insipidus. Thiazides are useful in treating renal calculi (kidney stones) and urolithiases (bladder stones) that result from hypercalciuria (high urine calcium levels). Thiazides increase the uptake of calcium in the distal tubules, to moderately reduce urinary calcium. Thiazides combined with potassium citrate, increased water intake and decreased dietary oxalate and sodium can slow or even reverse the formation of calcium-containing kidney stones. High-dose therapy with the thiazide-like diuretic indapamide can be used to treat idiopathic hypercalcinuria (high urine calcium with unknown cause).