Thiazides drugs

Acidosis and alkalosis are infrequent. Metabolic acidosis is a side effect of acetazolamide therapy and is due to bicarbonate loss in the PCT. All the K+-sparing diuretics can cause metabolic acidosis by H+ retention in the cells of the collecting duct. Metabolic alkalosis is associated with the loop and thiazide drugs. Reflex responses to volume depletion cause reabsorption of HCO-3 in the PCT and H+ secretion in the collecting tubule. 

Thiazide Diuretics. Thiazide drugs share a common chemical nucleus as well as a common mode of action. These drugs act primarily on the early portion of the distal tubule of the nephron, where they inhibit sodium reabsorption. By inhibiting sodium reabsorption, more sodium is retained within the nephron, creating an osmotic force that also retains more water in the nephron. Since more sodium and water are passed through the nephron, where they will ultimately be excreted from the body, a diuretic effect is produced. Thiazides are the most frequently used type of diuretic for hypertension. Specific types of thiazide drugs are listed in Table 21-3. 

Rodriguez SU, Leikin SL, Hiller MC. Neonatal thrombocytopenia associated with ante-partum administration of thiazide drugs. N Engl J Med 1964 270 881. ... 

Thiazide drugs can oppose the blood glucose-lowering effects of oral hypoglycemic drugs and insulin (48) (although this effect is rarely serious). 

Thiazide drugs have additive potassium-lowering effects with other drugs that reduce serum potassium, such as corticosteroids and carbenoxolone. Profound hypokalemia due to the latter combination has been reported to cause massive rhabdomyolysis and acute tubular necrosis (49). 

For the analysis of reserpine and hydrochlorothiazide, Butterfield et al. preferred a straight-phase separation. Because of the low concentration of the alkaloid compared to the thiazide drug, it was desirable to maximize the response of the former by eluting it from the column first. It was achieved by the straight-phase separation technique. On a microparticulate silica gel column, the drugs mentioned and a number of decomposition products could be analyzed (Table 8.13). 

A major progress was the use of diuretics, effective through an increase of urine flow and sodium excretion. They act directly on nephrons acting on various targets, including tubules and glomerules. The first thiazidic drug, chlorothiazide, became available in 1958, it was a real... 

The utility of a potent drug of this type is yet to be proved. However, ethacrynic acid has already proved life-saving in a number of patients that had become resistant to both mercurial and thiazide drugs (7, 20, 41). 

Thiazide diuretics have a venerable history as antihypertensive agents until the advent of the angiotensin-converting enzyme (ACE) inhibitors this class of drugs completely dominated first line therapy for hypertension. The size of thi.s market led until surprisingly recently to the syntheses of new sulfonamides related to the thiazides. Preparation of one of the last of these compounds starts by exhaustive reduction of the Diels-Alder adduct from cyclopentadiene and malei-mide (207). Nitrosation of the product (208), followed by reduction of the nitroso group of 209,... 

Tyrosine hydroxylase 1 Thiazide diuretics, a group of drugs with moderate diuretic activity, includes hydrochlorothiazide, chlorthalidone, and xipamide. They decrease active reabsorption of sodium and accompanying chloride by binding to the chloride site of the electroneutral Na+/CF cotransport system in the distal convoluted tubule and inhibiting its action. 

Diuretics are used in a variety of medical disorders. The primary health care provider selects the type of diuretic diat will most likely be effective for treatment of a specific disorder. In some instances, hypertension may be treated with the administration of an antihypertensive drug and a diuretic. The diuretics used for this combination tiierapy include the loop diuretics and the thiazides and related diuretics. The specific uses of each type of diuretic drug are discussed in the following sections. 

Amiloride (Midamor) is used in the treatment of CHF and hypertension and is often used with a thiazide diuretic. Spironolactone and triamterene are also used in tiie treatment of hypertension and edema caused by CHF, cirrhosis, and the nephrotic syndrome Amiloride, spironolactone, and triamterene are also available with hydrochlorothiazide, a thiazide diuretic that enhances tiie antihypertensive and diuretic effects of the drug combination while still conserving potassium. 

Additional adverse reactions of these drugs are listed in tiie Summary Drug Table Diuretics. When a potassium-sparing diuretic and a thiazide diuretic are given together, tiie adverse reactions associated with both drugp may be seen. 

Administration of thiazides and related diuretics may be associated with numerous adverse reactions. However, many patients take these drug s without... 

Calcium is contraindicated in patients with hypercalcemia or ventricular fibrillation and in patients taking digitalis. Calcium is used cautiously in patients with cardiac disease. Hypercalcemia may occur when calcium is administered with the thiazide diuretics. When calcium is administered with atenolol there is a decrease in Hie effect of atenolol, possibly resulting in decreased beta blockade. There is an increased risk of digitalis toxicity when digitalis preparations are administered with calcium. The clinical effect of verapamil may be decreased when the drug is administered with calcium. Concurrent ingestion of spinach or cereal may decrease file absorption of calcium supplements. 

Some drugs can cause hyperuricemia and gout, such as thiazide diuretics, niacin, pyrazinamide, cyclosporine, and occasionally, low-dose aspirin. 

Some drugs can cause hyperuricemia and gout, such as thiazide diuretics, niacin, pyrazinamide, cyclosporine, and occasionally, low-dose aspirin. In most cases, these drugs block uric acid secretion in the kidney. Long-term consequences of gout and hyperuricemia include joint destruction, tophi, and nephrolithiasis. 

Thiazide diuretics such as chlorothiazide act on the distal tubule, a portion of the tubule that is permeable to sodium. The mechanism of action of these diuretics involves inhibition of NaCl reabsorption by blocking the Na+, CL symporter in the luminal membrane. The thiazide diuretics are only moderately effective due to the location of their site of action. Approximately 90% of the filtered Na+ ions have already been reabsorbed when the filtrate reaches the distal tubule. These drugs may be used for treatment of edema associated with heart, liver, and renal disease. Thiazide diuretics are also widely used for the treatment of hypertension. 

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