Diuretics and thiazides

The answer is a. (Hardman, pp 705-706.) Patients at increased risk of developing hyperkalemia should not receive K-sparing diuretics. Potassiumsparing diuretics appear to block Na channels in the luminal membrane of the late distal tubules and the collecting duct. A mild excretion of Na occurs because of the relatively low capacity to reabsorb it in this portion of the nephron. Loop diuretics and thiazides typically increase K excretion. 

First, salt reabsorption in either the TAL or the DCT can increase when the other is blocked. Inhibition of both can therefore produce more than an additive diuretic response. Second, thiazide diuretics often produce a mild natriuresis in the proximal tubule that is usually masked by increased reabsorption in the TAL. The combination of loop diuretics and thiazides can therefore block Na + reabsorption, to some extent, from all three segments. 

The combination of loop diuretics and thiazides can mobilize large amounts of fluid, even in patients who have not responded to single agents. Therefore, close hemodynamic monitoring is essential. Routine outpatient use is not recommended. Furthermore, K+-wasting is extremely common and may require parenteral K+ administration with careful monitoring of fluid and electrolyte status. 

The actions of triamterene and spironolactone depend on renal prostaglandin production. As described above for loop diuretics and thiazides, the actions of triamterene and spironolactone can also be inhibited by NSAIDs under certain conditions. 

ANION EXCHANGE RESINS DIURETICS Both colestipol and colestyramine markedly 1 levels of loop diuretics and thiazides Colestipol and colestyramine bind diuretics in the intestine Give the anion exchange resin 3 hours after furosemide and 4 hours after thiazides (although the effect of hydrochlorothiazide may still be 1 by colestyramine)... 

AMPHOTERICIN DIURETICS-LOOP DIURETICS AND THIAZIDES Risk of hypokalaemia Additive effect Monitor potassium closely... 

The use of diuretics which promote heavy potassium loss (e.g., loop diuretics and thiazide diuretics) with carbamazepine therapy may precipitate a marked hyponatremia. 

No interactions are expected at standard therapeutic doses. At higher doses or with long-term use, licorice may potentiate potassium depletion of high-ceiling loop diuretics and thiazide diuretics, stimulant laxatives (Mills and Bone 2005), and corticosteroids such as prednisolone (Cheng et al. 2004 De Smet 1993), and may potentiate the action of cardiac glycosides such as digoxin (Kelly 1990). 

Each era of medicinal chemistry has been marked by intensive concentration on some structural type in a large number of laboratories. One need only look back in this book to the tables of sulfonamides, barbiturates, and thiazide diuretics, noting the small time span covered by the references to each list. The benzodiazepines have provided such a focus for the past decade. 

Fhtients taking a diuretic and a digitalis glycoside must be monitored closely. Thiazide and loop diuretics (see Chap. 46) may increase the risk and effects of toxicity. 

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. 

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. 

Older adults are particularly prone to fluid volume deficit and electrolyte imbalances (see Display 46-1) while taking a diuretic. The older adult is carefully monitored for hypokalemia (when taking the loop or thiazide diuretic and hyperkalemia (with the potassium-sparing diuretics... 

CARD IAC ARRHYTH MI AS AN D DIZZIN ESS. Patients receiving a diuretic (particularly a loop or thiazide diuretic) and a digitalis glycoside concurrently require frequent monitoring of the pulse rate and rhythm because of the possibility of cardiac arrhythmias. Any significant changes in the pulse rate and rhythm are immediately reported to the primary health care provider. 

Loop and thiazide diuretics patients with diabetes mellitus Blood glucometer test results for glucose may be elevated (blood) or the urine positive for glucose Contact the primary health care provider if results of home testing of blood glucose levels increase or if urine tests positive for glucose... 

Note The three reagents should be applied as quickly as possible after each other. In combination with the Ry value, and with UV detection before application of the reagent sequence this procedure allows the identification of therapeutic quantities of thiazide diuretics and methyldopa in urine together with a series of other therapeutic agents. Mobile phase residues e. g. acetic acid, should be completely removed from the chromatograms before application of the reagent sequence. 

Acetazolamide, captopril, ethacrynic acid, furosemide, hydralazine, methazolamide, methyldopa, procainamide, thiazide diuretics, and ticlopidine... 

P-Blockers and thiazide diuretics have proven benefits in reducing cardiovascular disease-associated morbidity and mortality.55 Tolerability permitting, these agents are to be considered first-line therapies in most transplant recipients. The... 

Rosner MH. Severe hyponatremia associated with the combined use of thiazide diuretics and selective serotonin reuptake inhibitors. Am J Med Sci 2004 327 109-111. 

The answer is b. (Katzung, pp 256-258J Amiloride is a K-sparing diuretic with a mild diuretic and natriuretic effect The parent compound is active, and the drug is excreted unchanged in the urine. Amiloride has a 24-hour duration of action and is usually administered with a thiazide or loop diuretic (e.g., furosemide) to prevent hypokalemia. The site of its... 

The answer is c. (Hardman, pp 704-706J Triamterene produces retention of the K ion by inhibiting in the collecting duct the reabsorption of Na, which is accompanied by the excretion of K ions. The loop diuretics furosemide and bumetanide cause as a possible adverse action the development of hypokalemia. In addition, thiazides (e g, hydrochlorothiazide) and the thiazide-related agents (e.g., metolazone) can cause the loss of K ions with the consequences of hypokalemia. Triamterene can be given with a loop diuretic or thiazide to prevent or correct the condition of hypokalemia. 

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