Hypokalemia diuretics

Diuretics can cause hypokalemia, hyperglycemia, and hypemricemia. After long-term treatment they may increase semm triglyceride and cholesterol... 

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. 

Hypokalemia. Hypokalemia associated with thia2ide diuretic therapy has been knpHcated in the increased incidence of cardiac arrhythmias and sudden death (82). Several large clinical trials have been conducted in which the effects of antihypertensive dmg therapy on the incidence of cardiovascular complications were studied. The antihypertensive regimen included diuretic therapy as the first dmg in a stepped care (SC) approach to lowering the blood pressure of hypertensive patients. 

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. 

The use of CA inhibitors as diuretics is limited by their propensity to cause metabolic acidosis and hypokalemia. Their use can be indicated in patients with metabolic alkalosis and secondary hyperaldosteronism resulting for example from aggressive use of loop diuretics. Furthermore, CA inhibitors are effective dtugs to produce a relatively alkaline urine for the treatment of cysteine and uric acid stones as well as for the accelerated excretion of salicylates. Perhaps the most common use of CA inhibitors is in the treatment of glaucoma. 

Hypokalemia is a reduction of plasma K+ concentration below 3.5 mM. Hypokalemia can result from a reduction in dietary K+ intake and from a shift of K into the intracellular space. The most common of hypokalemia, however, is renal K+ loss (i.e., caused by diuretics). 

ACE inhibitors do not completely block aldosterone synthesis. Since this steroid hormone is a potent inducer of fibrosis in the heart, specific antagonists, such as spironolactone and eplerenone, have recently been very successfully used in clinical trials in addition to ACE inhibitors to treat congestive heart failure [5]. Formerly, these drugs have only been applied as potassium-saving diuretics in oedematous diseases, hypertension, and hypokalemia as well as in primary hyperaldosteronism. Possible side effects of aldosterone antagonists include hyperkalemia and, in case of spironolactone, which is less specific for the mineralocorticoid receptor than eplerenone, also antiandrogenic and progestational actions. 

No significant interactions have been reported when tiie expectorants are used as directed. The exception is iodine products. Lithium and other antithyroid drug may potentiate the hypotliyroid effects of these drug if used concurrently with iodine products. When potassium-containing medications and potassium-sparing diuretics are administered with iodine products, the patient may experience hypokalemia, cardiac arrhythmias, or cardiac arrest. Thyroid function tests may also be altered by iodine... 

Diuretics (see Chap. 46) may be ordered for some patients receiving a cardiotonic drug. Diuretics, as well as odier conditions or factors, such as gastrointestinal suction, diarrhea, and old age, may produce low serum potassium levels (hypokalemia). The primary care provider may order a potassium salt to be given orally or IV. 

Electrolyte imbalances that may be seen during therapy with a diuretic include hyponatremia (low blood sodium) and hypokalemia (low blood potassium), although other imbalances may also be seen. See Chapter 58 and Display 58-2 for the signs and symptoms of electrolyte imbalances. The primary care provider is notified if any signs or symptoms of an electrolyte imbalance occur. 

CHF, hypertension, hypokalemia from other diuretics, prevention of hypokalemia in at-risk patients... 

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... 

When amphotericin B or diuretics are administered with ACTH, the potential for hypokalemia is increased. There may be an increased need for insulin or oral antidiabetic drag s in the patient with diabetes who is taking ACTH. There is a decreased effect of ACTH when the agent is administered with the barbiturates. Profound muscular depression is possible when ACTH is administered with the anticholinesterase drugp. Live virus vaccines taken while taking ACTH may potentiate virus replication, increase vaccine adverse reaction, and decrease the patient s antibody response to the vaccine... 

Potassium-sparing diuretics act on the late portion of the distal tubule and on the cortical collecting duct. As a result of their site of action, these diuretics also have a limited effect on diuresis compared to the loop diuretics (3% of the filtered Na+ ions may be excreted). However, the clinical advantage of these drugs is that the reabsorption of K+ ions is enhanced, reducing the risk of hypokalemia. 

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. 

Side effects of thiazides include hypokalemia, hypomagnesemia, hypercalcemia, hyperuricemia, hyperglycemia, hyperlipidemia, and sexual dysfunction. Loop diuretics have less effect on serum lipids and glucose, but hypocalcemia may occur. 

No unique signs or symptoms are associated with mild to moderate metabolic alkalosis. Some patients complain of symptoms related to the underlying disorder (e.g., muscle weakness with hypokalemia or postural dizziness with volume depletion) or have a history of vomiting, gastric drainage, or diuretic use. 

Many drugs can cause hypokalemia (Table 78-5) and it is most commonly seen with use of loop and thiazide diuretics. Other causes of hypokalemia include diarrhea, vomiting, and hypomagnesemia. 

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