Diuretic, potassium sparing thiazide

Thiazide and related diuretics, loop diuretics, potassium-sparing diuretics, carbonic anhydrase inhibitors, triamterene Avoid exposure to sunlight or ultraviolet light (sunlamps, tanning beds) because exposure may cause exaggerated sunburn (photosensitivity reaction). Wear sunscreen and protective clothing until tolerance is determined. 

Diuretics work by increasing the amount of sodium and fluids excreted by the kidneys. Less fluid means less total blood volume and improved circulation and blood pressure. There are five main classes of the drug loop diuretics, thiazide diuretics, potassium-sparing diuretics, osmotic diuretics, and carbonic anhydrase inhibitors. 

Thiazide diuretics are ineffective once the GFR becomes less than 25 mL/min, and loop diuretics are often used at high doses (e.g. furosemide 500 mg to 1 g daily) to gain an effect. Metolazone is effective when combined with a loop diuretic. Potassium-sparing diuretics such as amiloride are not recommended. Spironolactone is not generally used, but is beneficial in low dose for the treatment of heart failure even in patients on dialysis. Beta-blockers and calcium channel blockers are generally well tolerated. Any ankle swelling with calcium channel blockers must not be confused with fluid overload. 

UTHIUM LOOP DIURETICS, POTASSIUM-SPARING DIURETICS, ALDOSTERONE ANTAGONISTS, THIAZIDES t plasma concentrations of lithium, with risk of toxic effects L renal excretion of lithium Monitor clinically and by measuring blood lithium levels for lithium toxicity. Loop diuretics are safer than thiazides... 

Potassium Sparing Diuretics. Triamterene and amiloride, potassium sparing diuretics, by themselves produce only slight antihypertensive effects. The main use is to prevent or to treat the hypokalemia induced by thiazide-type and high ceiling loop diuretics, such as furosemide and bumetanide. 

Agents acting in the proximal tubule are seldom used to treat hypertension. Treatment is usually initiated with a thiazide-type diuretic. Chlorthalidone and indapamide are structurally different from thiazides but are functionally related. If renal function is severely impaired (i.e., serum creatinine above 2.5 mg/dl), a loop diuretic is needed. A potassium-sparing agent may be given with the diuretic to reduce the likelihood of hypokalemia. 

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... 

The nurse must closely observe patients receiving a potassium-sparing diuretic for signs of hyperkalemia (see Display 46-1), a serious and potentially fatal electrolyte imbalance The patient is closely monitored for hypokalemia during loop or thiazide diuretic therapy. A supplemental potassium supplement may be prescribed to prevent hypokalemia. The primary health care provider may also encourage the patient to include... 

Consider concomitant utilization of a potassium-sparing diuretic (e.g., spironolactone, amiloride, and triamterene) if renal losses because of loop or thiazide diuretics... 

Potassium-sparing diuretics are often coadministered with thiazide or loop diuretics in the treatment of edema and hypertension. In this way, edema fluid is lost to the urine while K+ ion balance is better maintained. The aldosterone antagonists are particularly useful in the treatment of primary hyperaldosteronism. 

Potassium-sparing diuretics are weak antihypertensives when used alone but provide an additive hypotensive effect when combined with thiazide or loop diuretics. Moreover, they counteract the potassium- and magnesiumlosing properties and perhaps glucose intolerance caused by other diuretics. 

Amiloride is a potassium-sparing diuretic, whereas hydrochlorthiazide is a thiazide diuretic that causes loss of potassium. Enalapril is an angiotensinconverting enzyme inhibitor that retains potassium, thereby counteracting the loss of potassium caused by the thiazide diuretic. 

Hypertension therapy suggests wide use of diuretics, including thiazide diuretics, drugs related to them, such as metolazone (21.3.20) and indapamide (21.3.26), furosemide (21.4.11), loop diuretics, as well as potassium sparing diuretics—spironolactone (21.5.8), triamterene (21.5.13), and amyloride (21.5.18). 

Other drugs that may interact with cardiac glycosides include the following Albuterol, amphotericin B, beta-blockers, calcium, disopyramide, loop diuretics, nondepolarizing muscle relaxants, potassium-sparing diuretics, succinylcholine, sympathomimetics, thiazide diuretics, thioamines, and thyroid hormones. 

Diuretics - Generally initiate therapy with a thiazide or other oral diuretic. Thiazide-type diuretics are drugs of choice hydrochlorothiazide or chlorthalidone are generally preferred. Reserve loop diuretics for selected patients. This therapy alone may control many cases of mild hypertension. Consider treating diuretic-induced hypokalemia (less than 3.5 mEq/L) with potassium supplementation or by adding a potassium-sparing diuretic to therapy. 

Drugs that may be affected by NSAIDs include the following Aminoglycosides, anticoagulants, ACE inhibitors, beta blockers, cyclosporine, dextromethorphan, digoxin, dipyridamole, hydantoins, lithium, loop diuretics, methotrexate, penicillamine, potassium-sparing diuretics, sympathomimetics, theophylline, thiazide diuretics. 

The potassium sparing diuretics are predominantly used in conjunction with thiazides or loop diuretics, with the aim to counteract the hypokalemia induced by the aforementioned types of diuretics. Enhanced natriuresis caused by thiazides or loop diuretics will lead to the following therapeutic benefits. 

Potassium-sparing diuretics, such as amiloride and triamterene. These agents reduce at the tubular level the reabsorption of sodium and water, whereas the excretion of potassium is diminished. Their primary effects are independent of aldosterone. They are slow-acting and weak diuretics, which are unsuitable as monotherapy of hypertension or heart failure. For this reason, they are always combined with thiazide or loop diuretics. Several combined preparations are commercially available. 

Thiazide diuretics are not effective with advanced renal insufficiency (serum creatinine level of 221 omol/l) and loop diuretics are needed, often at relatively large doses. Combining a loop diuretic with a long-acting thiazide diuretic, such as meto-lazone, is effective in patients resistant to a loop-diuretic alone. Potassium-sparing diuretics should be avoided in patients with renal insufficiency. 

B) The combination of a thiazide plus a potassium-sparing diuretic may yield an adequate diuretic response. 

Table 1.13. Most diuretics are designed to deal with conditions of edema by reducing the reabsorption of chlorides, sodium, and water as these are the major constituents of edema fluid. Diuretics are grouped into five main categories loop diuretics, thiazides, potassium-sparing diuretics, osmotic diuretics, and carbonic...

Ketanserin should not be combined with drugs that prolong the QT interval, e.g. class la anti-arrhythmics, amiodarone, sotalol, erythromycin. The risk of torsade de pointes secondary to hypokalaemia is increased when ketanserin is combined with thiazides or loop diuretics without concomitant use of a potassium-sparing diuretic or an angiotensin-converting enzyme (ACE) inhibitor, a 1 Antagonists... 

See Table 15-6. Potassium-sparing diuretics are most useful in states of mineralocorticoid excess or hyperaldosteronism (also called aldosteronism), due either to primary hypersecretion (Conn s syndrome, ectopic adrenocorticotropic hormone production) or secondary hyperaldosteronism (evoked by heart failure, hepatic cirrhosis, nephrotic syndrome, or other conditions associated with diminished effective intravascular volume). Use of diuretics such as thiazides or loop agents can cause or exacerbate volume contraction and may cause secondary hyperaldosteronism. In the setting of enhanced mineralocorticoid secretion and excessive delivery of Na+ to distal nephron sites, renal K+ wasting occurs. Potassium-sparing diuretics of either type may be used in this setting to blunt the K+ secretory response. 

POTASSIUM-SPARING DIURETICS LOOP AGENTS OR THIAZIDES... 

Triamterene is known as a potassium-sparing diuretic. It interferes with the Na -H exchange and can be used in combination with thiazides in order to help alleviate the electrolyte deficiency which can occur with diuretic treatment. 

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