Hypokalemia with diuretics

Use of a hERG blocker in a patient also taking drugs inducing electrolyte imbalance (e.g. risk of hypokalemia with diuretics) this is a pharmacodynamic interaction... 

Hypokalemia may occur if reboxetine is used with diuretics... 

Hypertension is often treated with diuretics. Diuretics are drugs that promote the Joss of sodium from the body, though some diuretics can cause the loss of potassium, resulting in hypokalemia. The use of dietary supplements of K to correct this hypokalemia has been shown to be of benefit and to result in decreases in blood pressure. The best source of potassium is plant food, as is strikingly apparent from the data in Table IG.l however, the interest in nonfood supplements of potassium continues. One problem with potassium salts is that they taste bad and can produce nausea. Hence, there has been some interest in the manufacture of aesthetically acceptable forms of potassium salts. One form, a mixture of NaCl and KCl, is useful for those who feel compelled to add sodium chloride to their food. One study revealed that NaCI-KCl mixtures are accepted and their use can result in a reduction of sodium intake. The study, which involved normotensive subjects, did not lead to any consistent change in blood pressure (Mickeisen rt nI., 1977). 

Early evidence linking thiazide-induced hypokalemia with dysrhythmias and sudden death was indirect and tenuous at best (50,51). One study suggested that diuretics are not responsible for the relation between hjrpokalemia and ventricular fibrillation in acute myocardial infarction (50). Chronic preoperative hypokalemia due to diuretics was not a risk factor for intraoperative dysrhjdhmias (52). Two large studies using 24-hour electrocardiographic monitoring failed to show a relation between diuretic-induced hypokalemia and ventricular dysrhythmias (53,54). 

Hjq)onatremia is the most common electrolyte abnormality in the general hospital population and is associated with a wide range of diseases and a variety of drugs. Acute hjq)onatremic encephalopathy can develop rapidly with diuretics, particularly thiazides. Women, all patients with hypokalemia, and those with a low sodium and/or solute intake are particularly susceptible to diuretic-induced hjq)onatremia. 

There are three diuretics available that impede the outflow of K+ rather than promote it as do the thiazide and loop diuretics. Even though hypokalemia with the potent saluretics can usually be prevented with oral potassium supplements, they can present problems of palatability and are sometimes not reliable in maintaining desirable K+ levels. It may therefore be preferable with certain patients to achieve diuresis without potassium depletion (Fig. 10-17). 

The primary treatment for hyponatremia owing to excess free water in the body is to remove the excess water and, if indicated, to treat the source of water retention. If diuretics are used to remove water, the nurse must monitor intake and output and electrolytes closely. Most diuretics work by removing sodium and water thus sodium levels may remain low initially. If the patient is symptomatic, sodium supplement may be given. The nurse should monitor for signs of hypernatremia (e.g., thirst, agitation, and hyperreflexia), which indicates that too much fluid was removed or too much sodium was infused. Potassium loss may occur with diuretics as well, so the nurse should monitor for hypokalemia. 6... 

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. 

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... 

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. 

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... 

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... 

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. 

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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