AHFS Drug Information AHFS Drug Information AHFS Drug Information
AHFS Drug Information AHFS Drug Information AHFS Drug Information
  AHFS DI       Essentials  
  Potassium Supplements (40:12) - 382780 
 

Potassium Supplements

AHFS Class: Replacement Preparations (40:12)

VA Class: TN430

Make a selection below to quickly jump to a specific section.

View the associated Essentials monograph.

Introduction

Potassium supplements are used as a source of potassium, an essential nutrient cation.

Uses

Potassium Depletion

Potassium supplements are used as a source of potassium cation for treatment or prevention of potassium depletion in patients in whom dietary measures are inadequate. Conditions which may indicate or result in potassium deficiency include vomiting, diarrhea, drainage of GI fluids, hyperadrenalism, malnutrition, debilitation, prolonged negative nitrogen balance, prolonged parenteral alimentation without addition of potassium, dialysis, metabolic alkalosis, metabolic or diabetic acidosis, GI tract abnormalities which result in poor absorption, certain renal diseases, and familial periodic paralysis characterized by hypokalemia. Potassium should be included in long-term electrolyte replacement regimens and has been recommended for routine prophylactic administration following surgery after adequate urine flow has been established. Administration of certain drugs including thiazide diuretics, carbonic anhydrase inhibitors, furosemide, ethacrynic acid, some corticosteroids, corticotropin, aminosalicylic acid, and amphotericin B may sometimes result in potassium depletion which may warrant potassium replacement therapy. Ingestion of potassium-rich foods and/or use of potassium-containing salt substitutes may prevent potassium depletion in patients receiving potassium-depleting drugs; however, judicious prophylactic administration of potassium may be advisable in selected patients during prolonged diuretic or corticosteroid therapy, especially if they are digitalized.

Potassium chloride is usually the salt of choice in the treatment of potassium depletion, since the chloride ion is required to correct hypochloremia which frequently accompanies potassium deficiency. In addition, hypochloremia may develop if the citrate, bicarbonate, gluconate, or another alkalinizing salt of potassium is administered, particularly in conjunction with chloride-restricted diets. In the rare instances in which metabolic acidosis exists concurrently with potassium depletion (e.g., renal tubular acidosis), alkalinizing salts of potassium are preferred.

Hypertension

Inadequate dietary intake of potassium may play an important role in the development of hypertension,101 102 103 and high dietary intake of potassium (e.g., with supplementation) may protect against the development of high blood pressure and improve blood pressure control in patients with hypertension.101 103 As a result, most experts currently recommend that an adequate intake of potassium101 103 (about 50–90 mEq daily)101 be maintained in hypertensive patients as part of lifestyle modifications,101 103 particularly in those unable to adequately reduce their sodium intake.103 Adequate intake of potassium also should be considered as a means of preventing the development of hypertension.101 103 Food sources high in potassium such as fruits and vegetables101 104 preferably should be used.101 Alternatively, potassium supplements or salt-substitutes or potassium-sparing diuretics can be used, particularly in patients receiving kaliuretic diuretics.101 In pooled analysis of data from 33 randomized controlled trials in which potassium supplementation was the only difference between intervention and control groups, such supplementation was associated with a reduction in mean systolic blood pressure of 3.11 mm Hg and a reduction in mean diastolic blood pressure of 1.97 mm Hg.103 The effects of potassium supplementation appeared to be particularly evident in patients exposed to high sodium intake.103

Acute Myocardial Infarction

Prevention of Ventricular Fibrillation

Potassium supplementation, combined with magnesium supplementation if necessary, has been used in patients with an acute myocardial infarction to reduce the risk of ventricular arrhythmias.105 Although the benefits of this strategy in preventing ventricular fibrillation following a myocardial infarction have not been confirmed by randomized clinical trial data, maintaining serum potassium and magnesium concentrations at levels exceeding 4 and 2 mEq/L, respectively, is considered sound clinical practice.105 In addition, clinical experience as well as observational data from coronary care unit populations indicate that hypokalemia is a risk factor for the development of ventricular fibrillation.105 110 111

Glucose-Insulin-Potassium Metabolic Modulation

Potassium chloride has been used IV early in the course of suspected acute myocardial infarction in combination with IV insulin injection (regular insulin) and dextrose (D-glucose) (referred to as glucose-insulin-potassium or GIK therapy) for metabolic modulation and potential beneficial effects on morbidity and mortality.105 106 107 108 109 Initial experience (from the pre-thrombolytic reperfusion era) with such early post-myocardial infarction metabolic modulation therapy showed substantial potential reductions in mortality associated with acute myocardial infarction.107 108 109 Pooled analysis of these early studies (randomized, placebo-controlled) showed a potential mortality reduction benefit of 28% (overall for 9 studies) to 48% (in a subset of 4 studies employing high-dose GIK), depending on the dosage and timing of therapy initiation relative to symptom onset.107 108 109 More recently, evidence of an even greater potential benefit was reported when early GIK therapy was combined with reperfusion (thrombolysis or primary percutaneous transluminal coronary angioplasty [PTCA]).105 106 107 Additional study is needed to elucidate further the role of GIK therapy in the management of acute myocardial infarction.105 106 107

In the recent study of metabolic modulation, 407 patients admitted within 24 hours of symptom onset of suspected myocardial infarction, regardless of age or ECG findings, were randomly assigned to high-dose GIK (IV infusion of 25% dextrose injection, insulin [human or nonhuman] 50 units/L, and potassium chloride 80 mEq/L at a rate of 1.5 mL/kg per hour for 24 hours), low-dose GIK (IV infusion of 10% dextrose injection, insulin [human or nonhuman] 20 units/L, and potassium chloride 40 mEq/L at a rate of 1 mL/kg per hour for 24 hours), or usual care as a control.105 106 GIK therapy was initiated on average within 10.1–11.4 hours of symptom onset.106 Because of the limited number of patients studied, analysis of results compared the combination of both GIK regimens (overall GIK-treated group) versus usual care as a control.106 In this study, a reduction in the composite end point of death, nonfatal severe heart failure (greater than Killip class 2), and nonfatal ventricular fibrillation was observed for the overall GIK-treated group as well as for the 252 (61.9%) patients who also underwent reperfusion.105 106 The latter group also showed a reduction in mortality rate (relative risk of 0.34; i.e., a 66% reduction), and a strong relationship was observed between the time of symptom onset and the beneficial effect of the infusion.105 106 A reduction in mortality rate also was shown for patients treated within 12 hours after symptom onset (relative risk of 0.43; i.e., a 57% reduction), both for the overall GIK-treated group and for those who also underwent reperfusion.105 106 Among patients in whom a 24-hour course of GIK infusion therapy was completed, mortality was reduced in both the overall GIK-treated (relative risk of 0.44; i.e., a 56% reduction) and in those who also underwent reperfusion (relative risk of 0.21; i.e., a 79% reduction).106 At 1-year follow-up, Kaplan-Meier curves showed attenuation of the treatment effect in both the overall GIK-treated group and those who also were reperfused, with a nonsignificant mortality reduction of 19 and 33%, respectively.106 Despite this attenuation of effect, a consistent, statistically significant mortality reduction was still present at 1 year for patients who received high-dose GIK combined with reperfusion (relative risk of 0.37; i.e., a 63% reduction).106 GIK therapy was well tolerated, with the principal differences between the GIK-treated and control groups being phlebitis (83% of patients received GIK via a peripheral IV line) and higher serum potassium concentration with GIK.106

Because results of this recent study showed that metabolic modulation with dextrose, insulin, and potassium (i.e., GIK therapy) is a feasible strategy in the early hours after an acute myocardial infarction, the American College of Cardiology (ACC),105 American Heart Association (AHA),105 and others106 107 encourage performance of a larger clinical trial to further elucidate the magnitude of potential benefit and role of such therapy in the management of myocardial infarction. However, the existing results have strong implications for incorporating this fairly simple, inexpensive, and well-tolerated therapy in the care of acute myocardial infarction patients worldwide.105 106

Other Uses

Potassium salts may be used cautiously to abolish arrhythmias of cardiac glycoside toxicity precipitated by a loss of potassium. It has been reported that elevation of plasma potassium concentrations by 0.5–1.5 mEq/L or to the upper limits of normal may be useful in the management of tachyarrhythmias following cardiac surgery. This regimen should not be used in patients with atrioventricular block, however, since potassium may further impair nodal conduction.

Limited data suggest that potassium may be useful in the treatment of thallium poisoning; however, such treatment is limited by the amount of thallium that can be released into the blood without worsening cerebral symptoms.

Dosage and Administration

Administration

The acetate, bicarbonate, chloride, citrate, and gluconate salts of potassium are administered orally. Potassium chloride, potassium acetate, and potassium phosphate may be administered by slow IV infusion. Rarely, potassium-containing injections are given by hypodermoclysis, in which case potassium concentrations should not exceed 10 mEq/L in order to avoid local pain. Whenever possible, potassium supplements should be given orally since the relatively slow absorption from the GI tract prevents sudden, large increases in plasma potassium concentrations. Oral potassium supplements should preferably be administered as liquid with or after meals with a full glass of water or fruit juice to minimize the possibility of GI irritation and a saline cathartic effect. Enteric-coated (no longer commercially available in the US) and wax matrix tablets must be swallowed and not allowed to dissolve in the mouth. Other commercially available oral dosage forms of potassium should be dissolved and/or diluted and administered according to the instructions of the manufacturer.

Potassium for injection concentrates must be diluted with a compatible IV solution prior to administration. Diluted solutions of potassium acetate, potassium chloride, and potassium phosphate for injection concentrates must be administered slowly. Potassium injections should generally be administered only in patients with adequate urine flow. In dehydrated patients, 1 liter of potassium-free fluid should be administered prior to initiating potassium therapy. Generally, potassium concentrations in IV fluids should not exceed 40 mEq/L and the rate of administration should not exceed 20 mEq/hour. However, higher potassium concentrations (e.g., 60–80 mEq/L) administered more rapidly occasionally may be needed initially in cases of severe hypokalemia and associated cardiac arrhythmias or for the management of diabetic ketoacidosis or the diuretic phase of acute renal failure. Local vascular intolerance may limit the ability to administer such concentrated solutions. In such cases, use of a large vein with a relatively high blood flow (e.g., femoral vein) or splitting and administering the dose in less concentrated solutions via 2 veins simultaneously can be considered. Administration of such concentrated potassium solutions via a subclavian, jugular, or right atrial catheter should be avoided since local potassium concentrations achieved in the heart may be high and potentially cardiotoxic. The ECG should be monitored closely when the rate of IV potassium administration exceeds 20 mEq/hour. Peaking of the T wave or other ECG changes associated with hyperkalemia (see Cautions: Hyperkalemia) indicate that the rate of potassium infusion is excessive and should be reduced.

Viaflex® Plus containers of potassium chloride injections should be checked for minute leaks by firmly squeezing the bag. The injection should be discarded if the container seal is not intact or leaks are found or if the solution is cloudy or contains a precipitate. The injection in plastic containers should not be used in series connections with other plastic containers, since such use could result in air embolism from residual air being drawn from the primary container before administration of fluid from the secondary container is complete.

Oral administration of potassium supplements or ingestion of potassium-rich foods should replace IV potassium therapy as soon as possible.

Dosage

Dosage of potassium supplements is usually expressed as mEq of potassium and depends on the requirements of the individual patient. The normal adult daily requirement and the usual dietary intake of potassium is 40–80 mEq; infants may require 2–3 mEq/kg or 40 mEq/m2 daily. Potassium replacement requirements can be estimated only by initial clinical condition and response, ECG monitoring, and/or plasma potassium determinations. Prophylactic administration of potassium supplements may be necessary in some patients in order to maintain plasma potassium concentration above 3.0 mEq/L. The average oral dosage of potassium supplements for the prevention of hypokalemia is about 20 mEq daily, and the usual oral dosage of potassium for the treatment of potassium depletion is 40–100 mEq or more daily. However, it is important to remember that dosage must be individualized for each patient. Forty mEq of potassium is provided by approximately:

3.9 g of potassium acetate

4.0 g of potassium bicarbonate

3.0 g of potassium chloride

4.3 g of potassium citrate

9.4 g of potassium gluconate

5.4 g of monobasic potassium phosphate

3.5 g of dibasic potassium phosphate

Oral potassium supplements are usually administered in 2–4 doses daily. To avoid serious hyperkalemia, replacement of potassium deficits must be undertaken gradually usually over a 3- to 7-day period depending on the severity of the deficit. Potassium dosage for adults should usually not exceed 150 mEq daily, and the dosage for young children should not exceed 3 mEq/kg daily. Close monitoring of the ECG and plasma potassium concentrations is essential during IV administration of potassium.

Acute Myocardial Infarction

Potassium chloride supplementation is used in patients with acute myocardial infarction to maintain serum potassium concentrations at greater than 4 mEq/L; serum magnesium concentrations should be maintained at greater than 2 mEq/L.105 Although the benefits of this strategy in preventing ventricular fibrillation following a myocardial infarction have not been confirmed by randomized clinical trial data, maintaining serum potassium and magnesium concentrations at these levels is considered sound clinical practice.105

Although additional study is needed to more fully elucidate the role of early (within 24 hours of symptom onset) metabolic modulation of suspected myocardial infarction (referred to as glucose-insulin-potassium or GIK therapy),105 106 107 potassium chloride has been infused IV at a concentration of 40 or 80 mEq/L in combination with 10 or 25% dextrose injection, respectively, and regular insulin 20 or 50 units/L, respectively.105 106 The low-dose solution (40 mEq potassium, 10% dextrose, and 20 units insulin [regular]) was infused at a rate of 1 mL/kg per hour for 24 hours and the high-dose solution (80 mEq potassium, 25% dextrose, and 50 units insulin [regular]) was infused at a rate of 1.5 mL/kg per hour for 24 hours.105 106 Although both regimens appear to be beneficial, current evidence suggests that the high-dose regimen may be more effective and therefore preferred.106 107 (See Acute Myocardial Infarction: Glucose-Insulin-Potassium Metabolic Modulation, in Uses.)

Cautions

GI and Other Local Effects

Adverse effects of potassium salts may include nausea, vomiting, diarrhea, flatulence, and abdominal pain or discomfort. Small bowel ulcerations have been reported following administration of enteric-coated potassium chloride tablets (no longer commercially available in the US). Ulcerations have been accompanied by stenosis, hemorrhage, obstruction, and perforation; surgery is frequently required and deaths have been reported. A few cases of small bowel ulceration, stricture, and perforation have been associated with wax matrix formulations of potassium chloride. Esophageal ulceration and stricture have occurred in patients with esophageal compression associated with an enlarged left atrium, and mouth ulceration occurred when a patient sucked rather than swallowed the wax matrix tablets. Following release of the drug from wax matrix tablets, the expended wax matrix is not absorbed systemically and may be detected in feces. Numerous wax matrices accumulated in a patient with partial obstruction of the lower bowel causing an impaction. To date, the incidence of GI lesions (ulceration, stricture, and perforation) with wax matrix tablets appears to be much lower than with enteric-coated (no longer commercially available in the US) tablets (less than 1 per 100,000 patient-years vs 40–50 per 100,000 patient-years). Extended-release tablets containing coated potassium chloride crystals are also formulated to minimize the likelihood of the drug causing GI lesions, but the frequency of GI lesions with these tablets currently is not known. Like enteric-coated tablets (no longer commercially available in the US), the wax matrix tablets and extended-release tablets containing coated crystals of the drug should be administered with caution and should be discontinued immediately if abdominal pain, distention, severe vomiting, or GI bleeding occurs. (See Cautions: Precautions and Contraindications.) Some authorities question the use of any potassium tablet, since use of dilute liquid preparations of potassium minimizes the risk of GI complications.

Pain at the site of injection and phlebitis may occur during IV administration of solutions containing 30 mEq or more potassium per liter.

Hyperkalemia

Hyperkalemia is the most common and serious hazard of potassium therapy. Since an exact measurement of potassium deficiency is not usually possible, potassium supplements should be administered slowly and with caution. The presence of adequate renal function must be confirmed, and frequent observations of the clinical status of the patient and periodic ECGs and/or determinations of plasma potassium concentrations should be made. ECG changes are probably the most important indicator of potassium toxicity and include tall, peaked T waves, depression of the ST segment, disappearance of the P wave, prolongation of the QT interval, and widening and slurring of the QRS complex. Clinical signs and symptoms of potassium overdosage include paresthesia of the extremities, listlessness, mental confusion, weakness or heaviness of the legs, flaccid paralysis, cold skin, gray pallor, peripheral vascular collapse with fall in blood pressure, cardiac arrhythmias, and heart block. Extremely high plasma potassium concentrations (8–11 mEq/L) may cause death from cardiac depression, arrhythmias, or arrest. It has been suggested that hyperkalemia may decrease the excitability of the myocardium to electrical stimulation resulting in the possibility that the myocardium may not respond to implanted pacemakers.

Except in the presence of severe renal impairment, hyperkalemia is not likely to result from oral administration or from slow IV administration of dilute solutions of potassium. Nonetheless, hyperkalemia can occur from therapeutic doses of potassium salts and, when detected, must be treated immediately since lethal plasma potassium concentrations can be reached within a few hours. Hyperkalemia may result from rapid IV administration of potassium solutions. Hyperkalemia has occurred following addition of concentrated potassium chloride solutions to infusions from a hanging flexible plastic container, apparently as a result of pooling of the concentrated potassium solution at the base of the container and infusion of undiluted solution. Squeezing the container did not facilitate mixing but tended to pump the concentrated solution into the infusion chamber. Mixing of the solutions can be achieved if the plastic container is inverted during the addition of potassium solutions and subsequently agitated and/or kneaded.

Treatment of hyperkalemia depends on its severity and various regimens have been recommended. It must be kept in mind that rapid lowering of plasma potassium concentrations in digitalized patients can cause cardiac glycoside toxicity. Administration of potassium-rich foods and drugs and potassium-sparing diuretics must be discontinued. In patients with severe hyperkalemia, measures which facilitate shift of potassium into cells, such as administration of sodium bicarbonate, a calcium salt, and/or dextrose with or without insulin, have been recommended. In patients with plasma potassium concentrations greater than 6.5 mEq/L, IV infusion of 40–160 mEq of sodium bicarbonate over a 5-minute period has been recommended. This dose may be repeated after 10–15 minutes if ECG abnormalities persist. Dextrose therapy usually consists of IV infusion of 300–500 mL of 10–25% dextrose injection containing 5–10 units of insulin per 20 grams of dextrose over a 1-hour period. Some clinicians report that dextrose is less reliable and does not produce effects as rapidly as does sodium bicarbonate. In addition, studies indicate that the addition of insulin to an infusion solution results in adsorption of insulin to the glass and tubing. For this reason, it has been recommended that insulin be given as a separate injection. Patients whose ECGs show absent P waves or a broad QRS complex and who are not receiving cardiac glycosides should immediately be given 0.5–1 g (5–10 mL of a 10% solution) of calcium gluconate or another calcium salt IV over a 2-minute period (with continuous ECG monitoring) to antagonize the cardiotoxic effects of potassium. If ECG abnormalities persist, repeated doses of the calcium salt may be given, allowing 1–2 minutes between doses. When hyperkalemia is associated with water loss, administration of potassium-free fluids may be useful to decrease plasma potassium concentrations.

When the ECG approaches normal, efforts should be directed toward removal of excess potassium from the body. Some adsorption and/or exchange of potassium may be accomplished by administration of sodium polystyrene sulfonate orally or as a retention enema. Hemodialysis or peritoneal dialysis will reduce plasma potassium concentrations and may be required in patients with renal insufficiency. Administration of large doses of sodium chloride has been recommended to increase urinary excretion of potassium in patients with functional kidneys. Other drugs which have been used in an effort to reduce plasma potassium concentrations include testosterone to promote anabolism, and desoxycorticosterone acetate in patients with adrenal insufficiency who have adequate renal function.

Precautions and Contraindications

Potassium supplements should be administered with caution in patients with cardiac disease. These drugs may intensify symptoms of myotonia congenita. Potassium supplements should not be administered to patients receiving potassium-sparing drugs such as amiloride, spironolactone, and triamterene. Potassium should generally not be given in the immediate postoperative period until urine flow is established. In patients with renal impairment, its use must be carefully controlled by frequent determinations of plasma potassium concentrations.

Because intestinal and gastric ulceration and bleeding have occurred with extended-release potassium chloride preparations, these dosage forms of the drug should be reserved for patients who cannot tolerate or refuse to take liquid or effervescent potassium preparations or for those in whom there is a problem of compliance with these latter dosage forms. If abdominal pain, distension, severe vomiting, or GI bleeding occurs in patients receiving an extended-release preparation, the drug should be discontinued immediately and the possibility of intestinal obstruction or perforation considered. Because Micro-K® LS contains docusate sodium as a dispersing agent, minor changes in consistency of feces may commonly occur; these changes are generally well tolerated. However, rarely, patients may experience diarrhea and cramping or abdominal pain. Patients with severe or chronic diarrhea or who are dehydrated generally should not receive supplemental potassium therapy using Micro-K® LS.

Some preparations of potassium contain the dye tartrazine (FD&C yellow No. 5), which may cause allergic reactions including bronchial asthma in susceptible individuals. Although the incidence of tartrazine sensitivity is low, it frequently occurs in patients who are sensitive to aspirin.

Potassium supplements are contraindicated in patients with severe renal impairment with oliguria, anuria, or azotemia; untreated chronic adrenocortical insufficiency (Addison’s disease); the hyperkalemic form of familial periodic paralysis or other hyperkalemias; acute dehydration; heat cramps; or extensive tissue breakdown such as severe burns. Wax matrix formulations of potassium chloride should not be administered to patients with esophageal compression caused by an enlarged left atrium; a liquid preparation of potassium should be used in these patients. Solid oral dosage forms of potassium supplements are contraindicated in patients in whom there is a structural, pathological (e.g., diabetic gastroparesis), and/or pharmacologic (e.g., induced by anticholinergic agents) cause for arrest or delay in passage of the dosage form through the GI tract; an oral liquid preparation of potassium should be used in these patients.

Pharmacology

Potassium is the major cation of intracellular fluid and is essential for maintenance of acid-base balance, isotonicity, and electrodynamic characteristics of the cell. Potassium is an important activator in many enzymatic reactions and is essential to a number of physiologic processes including transmission of nerve impulses; contraction of cardiac, smooth, and skeletal muscles; gastric secretion; renal function; tissue synthesis; and carbohydrate metabolism.

The mechanism of beneficial effect of metabolic modulation with potassium in combination with dextrose (D-glucose) and insulin (referred to as glucose-insulin-potassium or GIK therapy) following an acute myocardial infarction remains to be more fully elucidated.107 109 However, current evidence suggests that several metabolic mechanisms may be involved in the protective effects of GIK on ischemic myocardium.107 109 GIK decreases both circulating concentrations of free fatty acids (FFAs) and myocardial uptake of FFAs.107 Increased FFAs have been shown to be toxic to ischemic myocardium and are associated with increased membrane damage, arrhythmias, and decreased cardiac function.107 The potential beneficial effects of GIK against FFAs may be particularly important in patients with high circulating concentrations of catecholamines and in those receiving heparin since catecholamines and heparin both increase serum FFA concentrations.107 The early rationale for GIK administration in acute myocardial infarction was stimulation of myocardial potassium uptake by insulin via Na+-K+-ATPase and provision of glucose (substrate) for glycolic ATP production.107 109 Although the clinical importance of providing a relatively small increase in ischemic glycolic ATP synthesis resulting from provision of increased glyocolic substrate has been questioned by some, such an increase, even if relatively small, acts as a “trap” for inorganic phosphates and ADP, with resultant amplification of free energy yield beyond that resulting from increased glycolic ATP synthesis per se.107 In addition, the intracellular location of glycolic enzymes may provide particular value from glycolic ATP in the maintenance of critical membrane functions such as calcium and sodium homeostasis.107 High glucose substrate increases myocyte resistance to the toxic effects of the increased calcium concentration that accompanies hypoxia.107

Pharmacokinetics

Absorption

Potassium salts are well absorbed from the GI tract. Enteric-coated potassium chloride tablets (no longer commercially available in the US) pass through the stomach releasing the drug in the small intestine and may produce dangerously high, localized concentrations of potassium chloride. Ingestion of sugar-coated tablets containing potassium chloride imbedded in a wax matrix (e.g., Kaon-Cl®, Slow-K®) produces a slow release of the drug. The wax matrix and potassium chloride crystals are blended so that the salt can be slowly leached from the tablet by GI fluids, and thus the potassium chloride is gradually released over a large segment of the intestine. Compared to liquid preparations, absorption of potassium from a single dose in these wax matrix formulations is somewhat delayed, probably because of the time required for dissolution of the drug. However, when potassium chloride is administered chronically, the bioavailability of potassium from the wax matrix preparations appears to be similar to that of liquid preparations of the drug. Dangerously high, localized concentrations of potassium chloride are not likely to occur with this dosage form unless blockage of passage of the tablet through the GI tract occurs. Similarly, extended-release granules for suspension and tablets containing coated potassium chloride crystals produce a slow release of the drug and minimize the likelihood of high, localized concentrations in the GI tract.

Distribution

Potassium first enters the extracellular fluid and is then actively transported into the cells where its concentration is up to 40 times that outside the cell. Dextrose, insulin, and oxygen facilitate movement of potassium into cells. In healthy adults, plasma potassium concentrations generally range from 3.5–5 mEq/L. Plasma concentrations up to 7.7 mEq/L may be normal in neonates. Plasma potassium concentrations, however, are not necessarily accurate indications of cellular potassium concentrations; cellular deficits can occur without decreases in plasma potassium concentrations and hypokalemia may occur without substantial depletion of cellular potassium. Changes in extracellular fluid pH produce reciprocal effects on plasma potassium concentrations. A change of 0.1 unit in plasma pH has been reported to produce an inverse change of 0.6 mEq/L in plasma potassium concentration. Potassium concentrations in gastric and intestinal secretions are higher than plasma concentrations, and diarrheal fluid may contain up to 60 mEq/L.

Elimination

Potassium is excreted mainly by the kidneys. The cation is filtered by the glomeruli, reabsorbed in the proximal tubule, and secreted in the distal tubule, the site of sodium-potassium exchange. Tubular secretion of potassium is also influenced by chloride ion concentration, hydrogen ion exchange, acid-base equilibrium, and adrenal hormones. Healthy patients on potassium-free diets usually excrete 40–50 mEq of potassium daily. Surgery and/or tissue injury result in increased urinary excretion of potassium which may continue for several days. Postoperative patients or patients under stress of disease with normal kidneys may excrete up to 80–90 mEq of potassium daily, even though they are not receiving any potassium. Small amounts of potassium may be excreted via the skin and intestinal tract, but most of the potassium excreted into the intestine is later reabsorbed.

Chemistry and Stability

Chemistry

Potassium supplements are used in the prevention or treatment of potassium depletion. For oral administration, the acetate, bicarbonate, chloride, citrate, and gluconate salts of potassium are available as single ingredients and/or components of combination products. Potassium acetate, potassium chloride, and potassium phosphate are available as concentrates for injection that must be diluted prior to IV administration (for injection concentrate). In addition, potassium chloride is a component of several multiple electrolyte IV infusion fluids. The salts used as potassium supplements are very soluble or freely soluble in water. Potassium chloride for injection concentrate has a pH of 4–8, potassium acetate for injection concentrate has a pH of 7.1–7.7, and potassium phosphates for injection concentrate has a pH of 7–7.8.

Stability

Some commercially available injections of potassium chloride are provided in Viaflex® Plus containers. Viaflex® Plus plastic containers are fabricated from specially formulated polyvinyl chloride (PL 146® plastic). The amount of water that can permeate from inside the container into the overwrap is insufficient to substantially affect the solution. Solutions in contact with the plastic can leach out some of its chemical components in very small amounts (e.g., bis(2-ethylhexyl)phthalate [BEHP, DEHP] in up to 5 ppm) within the expiration period of the injection; however, safety of the plastic has been confirmed in tests in animals according to USP biological tests for plastic containers as well as by tissue culture toxicity studies.

Potassium chloride, potassium acetate, and potassium phosphates concentrates for injection have been reported to be physically incompatible with IV solutions containing various drugs. Published data are too varied and/or limited to permit generalizations, and specialized references should be consulted for specific compatibility information.

Preparations

Potassium Acetate
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

For injection concentrate

2 mEq of K+/mL and CH3COO-/mL*

Potassium Acetate Injection

Abraxis, American Regent, Hospira

2 mEq of K+/mL and CH3COO-/mL pharmacy bulk package*

Potassium Acetate Injection

American Regent, Hospira

Potassium Acetate Injection MaxiVial®

Abraxis

4 mEq of K+/mL and CH3COO-/mL*

Potassium Acetate Injection

Abraxis, American Regent

* available by nonproprietary name

Potassium Bicarbonate
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Tablets, for solution

6.5 mEq of K+

Quic-K®

Western Research

25 mEq of K+*

K+ Care® Effervescent Tablets

Alra

K-Lyte® Effervescent Tablets (with citric acid 2.1 g)

Bristol-Myers Squibb

Klor-Con®/EF (with citric acid 2.1 g; sugar-free)

Upsher-Smith

Potassium Bicarbonate Effervescent Tablets

Major, Schein, Teva, United Research

* available by nonproprietary name

Potassium Chloride
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Capsules, extended-release

8 mEq of K+ and Cl*

Micro-K®

Ther-Rx

Potassium Chloride Extended-Release Capsules

Ethex

10 mEq of K+ and Cl*

Micro-K®

Ther-Rx

For solution

20 mEq of K+ and Cl per packet*

K+ Care®

Alra

K-Lor®

Abbott

Kay Ciel® (sugar-free)

Forest

Klor-Con® Powder (sugar-free)

Upsher-Smith

25 mEq of K+ and Cl per packet

Klor-Con®/25 Powder (sugar-free)

Upsher-Smith

Solution

6.7 mEq of K+/5 mL and Cl-/5 mL*

Kaochlor® 10% (with alcohol 5% and tartrazine)

Savage

Kay Ciel® (with alcohol 4% and parabens; sugar-free)

Forest

10 mEq of K+/5 mL and Cl-/5 mL*

Rum-K® (sugar-free)

Fleming

13.3 mEq of K+/5 mL and Cl-/5 mL*

Kaon-Cl® 20% Elixir (with alcohol 5%; sugar-free)

Savage

Tablets, extended-release

8 mEq of K+ and Cl*

Potassium Chloride Extended Release Tablets

Major, United Research

Slow-K® (with parabens and povidone)

Novartis

10 mEq of K+ and Cl

Kaon-Cl-10®

Savage

Tablets, extended-release (containing coated potassium chloride crystals)

10 mEq of K+ and Cl

K-Dur® 10

Key

20 mEq of K+ and Cl

K-Dur® 20 (scored)

Key

Tablets, extended-release, film-coated

8 mEq of K+ and Cl*

K+ 8®

Alra

Klor-Con® 8 (with propylene glycol)

Upsher-Smith

Potassium Chloride Extended Release Tablets

Major, Teva

10 mEq of K+ and Cl*

K+ 10®

Alra

Klor-Con® 10 (with propylene glycol)

Upsher-Smith

Klotrix® (with povidone)

Bristol-Myers Squibb

K-Tab® Filmtab®

Abbott

Potassium Chloride Extended Release Tablets

Major, Teva, United Research

Tablets, film-coated

2.5 mEq of K+ and Cl*

Potassium Chloride Tablets

Western Research

10 mEq K+ and CI*

Potassium Chloride Tablets

Western Research
Parenteral

For injection concentrate

1.5 mEq of K+ and Cl per mL*

Potassium Chloride for Injection Concentrate

Hospira

2 mEq of K+ and Cl per mL*

2 mEq of K+ and Cl per mL pharmacy bulk package*

Potassium Chloride for Injection Concentrate

Abraxis, Baxter, Braun, Hospira

For injection concentrate, for IV infusion

0.1 mEq of K+ and Cl per mL (10 mEq)*

Potassium Chloride for Injection Concentrate

Hospira

Potassium Chloride Injection Highly Concentrated (Viaflex®)

Baxter

0.2 mEq of K+ and Cl per mL (10 and 20 mEq)*

Potassium Chloride Injection Highly Concentrated (Viaflex®)

Baxter

0.3 mEq of K+ and Cl per mL (30 mEq)*

Potassium Chloride Injection Highly Concentrated (Viaflex®)

Baxter

0.4 mEq of K+ and Cl per mL (20 and 40 mEq)*

Potassium Chloride Injection Highly Concentrated (Viaflex®)

Baxter

* available by nonproprietary name

Potassium Chloride in Dextrose Injection
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

Injection, for IV infusion only

10 mEq of K+ per L in 5% Dextrose*

10 mEq/L Potassium Chloride in 5% Dextrose Injection (Viaflex®)

Baxter

20 mEq of K+ per L in 5% Dextrose*

20 mEq/L Potassium Chloride in 5% Dextrose Injection (Viaflex®)

Baxter

20 mEq/L 0.15% Potassium Chloride in 5% Dextrose Injection

Braun, Hospira

30 mEq of K+ per L in 5% Dextrose*

30 mEq/L Potassium Chloride in 5% Dextrose Injection (Viaflex®)

Baxter

30 mEq/L 0.224% Potassium Chloride in 5% Dextrose Injection

Hospira

40 mEq of K+ per L in 5% Dextrose*

40 mEq/L Potassium Chloride in 5% Dextrose Injection (Viaflex®)

Baxter

40 mEq 0.3% Potassium Chloride in 5% Dextrose Injection

Braun, Hospira

* available by nonproprietary name

Potassium Chloride in Sodium Chloride Injection
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

Injection, for IV infusion only

20 mEq of K+ per L in 0.9% Sodium Chloride*

20 mEq/L Potassium Chloride in 0.9% Sodium Chloride Injection (Viaflex®)

Baxter

20 mEq/L 0.15% Potassium Chloride in 0.9% Sodium Chloride Injection

Braun, Hospira

40 mEq of K+ per L in 0.9% Sodium Chloride*

40 mEq/L Potassium Chloride in 0.9% Sodium Chloride Injection (Viaflex®)

Baxter

40 mEq/L 0.3% Potassium Chloride in 0.9% Sodium Chloride Injection

Hospira

* available by nonproprietary name

Potassium Chloride in Dextrose and Lactated Ringer’s Injection
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

Injection, for IV infusion only

20 mEq of K+ per L in 5% Dextrose and Lactated Ringer’s*

20 mEq/L Potassium Chloride in 5% Dextrose and Lactated Ringer’s Injection (Viaflex®)

Baxter

20 mEq/L 0.15% Potassium Chloride in 5% Dextrose and Lactated Ringer’s Injection

Hospira

40 mEq of K+ per L in 5% Dextrose and Lactated Ringer’s*

40 mEq/L Potassium Chloride in 5% Dextrose and Lactated Ringer’s Injection (Viaflex®)

Baxter

40 mEq/L 0.3% Potassium Chloride in 5% Dextrose and Lactated Ringer’s Injection

Hospira

* available by nonproprietary name

Potassium Chloride in Dextrose and Sodium Chloride Injection
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

Injection, for IV infusion only

10 mEq of K+ per L in 5% Dextrose and 0.2–0.225% Sodium Chloride*

10 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection (Viaflex®)

Baxter

0.075% 10 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection

Braun

10 mEq/L 0.075% Potassium Chloride in 5% Dextrose and 0.225% Sodium Chloride Injection

Hospira

10 mEq of K+ per L in 5% Dextrose and 0.3–0.33% Sodium Chloride*

10 mEq/L (0.075%) Potassium Chloride in 5% Dextrose and 3% Sodium Chloride Injection

Hospira

10 mEq/L Potassium Chloride in 5% Dextrose and 0.33% Sodium Chloride Injection (Viaflex®)

Baxter

10 mEq of K+ per L in 5% Dextrose and 0.45% Sodium Chloride*

10 mEq/L Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection (Viaflex®)

Baxter

10 mEq/L 0.075% Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection

Braun, Hospira

20 mEq of K+ per L in 5% Dextrose and 0.2–0.225% Sodium Chloride*

20 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection (Viaflex®)

Baxter

20 mEq/L 0.15% Potassium Chloride in 5% Dextrose and 0.225% Sodium Chloride Injection

Hospira

0.15% 20 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection

Braun

20 mEq K+ per L in 5% Dextrose and 0.3–0.33% Sodium Chloride*

20 mEq/L Potassium Chloride in 5% Dextrose and 0.33% Sodium Chloride Injection (Viaflex®)

Baxter

20 mEq/L 0.15% Potassium Chloride in 5% Dextrose and 0.3% Sodium Chloride Injection

Braun, Hospira

20 mEq of K+ per L in 5% Dextrose and 0.45% Sodium Chloride*

20 mEq Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection (Viaflex®)

Baxter

20 mEq/L 0.15% Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection

Braun, Hospira

20 mEq of K+ per L in 5% Dextrose and 0.9% Sodium Chloride*

20 mEq/L Potassium Chloride in 5% Dextrose and 0.9% Sodium Chloride Injection (Viaflex®)

Baxter

20 mEq 0.15% Potassium Chloride in 5% Dextrose and 0.9% Sodium Chloride Injection

Braun, Hospira

20 mEq of K+ per L in 10% Dextrose and 0.2% Sodium Chloride*

0.15% 20 mEq/L Potassium Chloride in 10% Dextrose and 0.2% Sodium Chloride Injection

Braun

30 mEq of K+ per L in 5% Dextrose and 0.2–0.225% Sodium Chloride*

30 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection (Viaflex®)

Baxter

30 mEq/L 0.224% Potassium Chloride in 5% Dextrose and 0.225% Sodium Chloride Injection

Hospira

0.22% 30 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection

Braun

30 mEq of K+ per L in 5% Dextrose and 0.3–0.33% Sodium Chloride*

30 mEq/L Potassium Chloride in 5% Dextrose and 0.33% Sodium Chloride Injection (Viaflex®)

Baxter

30 mEq/L 0.224% Potassium Chloride in 5% Dextrose and 0.3% Sodium Chloride Injection

Hospira

30 mEq of K+ per L in 5% Dextrose and 0.45% Sodium Chloride*

30 mEq/L Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection (Viaflex®)

Baxter

30 mEq/L 0.224% Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection

Hospira

0.22% 30 mEq/L Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection

Braun

40 mEq of K+ per L in 5% Dextrose and 0.2–0.225% Sodium Chloride*

40 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection (Viaflex®)

Baxter

40 mEq/L 0.3% Potassium Chloride in 5% Dextrose and 0.225% Sodium Chloride Injection

Hospira

0.3% 40 mEq/L Potassium Chloride in 5% Dextrose and 0.2% Sodium Chloride Injection

Braun

40 mEq of K+ per L in 5% Dextrose and 0.3–0.33% Sodium Chloride*

40 mEq/L Potassium Chloride in 5% Dextrose and 0.33% Sodium Chloride Injection

Baxter

40 mEq/L 0.3% Potassium Chloride in 5% Dextrose and 0.3% Sodium Chloride Injection

Hospira

40 mEq of K+ per L in 5% Dextrose and 0.45% Sodium Chloride*

40 mEq/L Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection (Viaflex®)

Baxter

40 mEq/L 0.3% Potassium Chloride in 5% Dextrose and 0.45% Sodium Chloride Injection

Braun, Hospira

40 mEq of K+ per L in 5% Dextrose and 0.9% Sodium Chloride*

40 mEq/L Potassium Chloride in 5% Dextrose and 0.9% Sodium Chloride Injection (Viaflex®)

Baxter

* available by nonproprietary name

Potassium Chloride in Water
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

Injection, for IV infusion only

0.1 mEq per mL (10 mEq)*

Potassium Chloride in Water for Injection (Premixed) (LifeCare®)

Hospira

0.2 mEq per mL (10 and 20 mEq)*

Potassium Chloride in Water for Injection (Premixed) (LifeCare®)

Hospira

0.3 mEq per mL (30 mEq)*

Chloride in Water for Injection (Premixed) (LifeCare®)

Hospira

0.4 mEq per mL (20 and 40 mEq)*

Potassium Chloride in Water for Injection (Premixed) (LifeCare®)

Hospira

* available by nonproprietary name

Potassium Gluconate
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Elixir

6.7 mEq of K+ per 5 mL*

Kaon® Elixir (with alcohol 5%; sugar-free)

Savage

Tablets

2 mEq of K+*

Glu-K®

Western Research

* available by nonproprietary name

Potassium Acetate, Potassium Bicarbonate, and Potassium Citrate
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Solution

15 mEq of K+ (provided by potassium acetate 500 mg, potassium bicarbonate 500 mg, and potassium citrate 500 mg) per 5 mL

Tri-K®

Century
Potassium Bicarbonate and Potassium Chloride
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Tablets, for solution

25 mEq of K+ and Cl (provided by potassium bicarbonate 0.5 g and potassium chloride 1.5 g)*

Potassium Effervescent Tablets

Teva

25 mEq of K+ and Cl (provided by potassium bicarbonate 0.5 g, potassium chloride 1.5 g, and lysine hydrochloride 0.91 g)

K-Lyte/CL® Effervescent Tablets (with citric acid 0.55 g)

Bristol-Myers Squibb

50 mEq of K+ and Cl (provided by potassium bicarbonate 2 g, potassium chloride 2.24 g, and lysine hydrochloride 3.65 g)

K-Lyte/CL® 50 Effervescent Tablets (with citric acid 1 g)

Bristol-Myers Squibb

* available by nonproprietary name

Potassium Bicarbonate and Potassium Citrate
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Tablets, for solution

50 mEq of K+ (provided by potassium bicarbonate 2.5 g and potassium citrate 2.7 g)

K-Lyte® DS Effervescent Tablets (with citric acid 2.1 g)

Bristol-Myers Squibb
Potassium Citrate and Potassium Gluconate
RoutesFormsStrengthsBrand NamesManufacturer
Oral

Solution

6.7 mEq of K+ (provided by potassium citrate 0.17 g and potassium gluconate 1.17 g) per 5 mL

Twin-K® (with sorbitol)

Boots
Potassium Phosphates
RoutesFormsStrengthsBrand NamesManufacturer
Parenteral

For injection concentrate

4.4 mEq of K+ and 3 mM of P (provided by potassium phosphate dibasic 236 mg and potassium phosphate monobasic 224 mg) per mL*

Potassium Phosphates Injection

Abraxis, American Regent, Hospira

4.4 mEq of K+ and 3 mM of P (provided by potassium phosphate dibasic 236 mg and potassium phosphate monobasic 224 mg) per mL pharmacy bulk package*

Potassium Phosphates Injection

Hospira

* available by nonproprietary name

Comparative Pricing

This pricing information is subject to change at the sole discretion of DS Pharmacy. For the most current and up-to-date pricing information, please visit www.drugstore.com.

Colyte with Flavor Packs 240GM Solution for Reconstitution (ALAVEN PHARMACEUTICALS, LLC): 4000/$30 or 8000/$55.2

Kaon-Cl 40 MEQ/15ML(20%) Liquid (SAVAGE): 480/$49.01 or 1440/$81.94

K-Dur 10MEQ Controlled-release Tablets (KEY): 100/$38.96 or 300/$105.42

Klor-Con 20MEQ Pack (UPSHER-SMITH): 100/$22.99 or 300/$54.96

Klor-Con 25MEQ Pack (UPSHER-SMITH): 30/$15.99 or 60/$25.98

Klor-Con 8MEQ Controlled-release Tablets (UPSHER-SMITH): 30/$12.99 or 60/$14.98

Klor-Con M15 15MEQ Controlled-release Tablets (UPSHER-SMITH): 30/$13.4 or 90/$37.97

Klor-Con M20 20MEQ Controlled-release Tablets (UPSHER-SMITH): 100/$43.99 or 300/$122.97

Micro-K 10MEQ Controlled-release Capsules (THER RX): 30/$33.59 or 90/$73.89

Potassium Chloride 40 MEQ/15ML(20%) Liquid (QUALITEST): 240/$12 or 480/$19.97

Potassium Chloride CR 10MEQ Controlled-release Capsules (ETHEX): 30/$26.27 or 60/$37.75

Potassium Chloride CR 10MEQ Controlled-release Tablets (SANDOZ): 100/$19.99 or 300/$45.96

Potassium Chloride Crys CR 10MEQ Controlled-release Tablets (SCHERING): 100/$24.99 or 300/$64.98

Potassium Chloride Crys CR 20MEQ Controlled-release Tablets (SCHERING): 90/$17 or 180/$20

Rum-K-SF 15% Liquid (FLEMING): 480/$46.99 or 1440/$133.92

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

Selected Revisions July 2006, © Copyright, September 1976, American Society of Health-System Pharmacists, Inc. 7272 Wisconsin Avenue, Bethesda, MD 20814.

ASHP

References

Only references cited for selected revisions after 1984 are available electronically.

101. National Heart, Lung, and Blood Institute National High Blood Pressure Education Program. The sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI). Bethesda, MD: National Institutes of Health. (NIH publication No. 98-4080.)

102. Stamler R, Stamler J, Grandits GA. Relation of body mass and alcohol, nutrient, fiber, and caffeine intakes to blood pressure in the special intervention and usual care groups in the Multiple Risk Factor Intervention Trial. Am J Clin Nutr. 1997; 65(Suppl):338-65S.

103. Whelton PK, He J, Cutler JA et al. Effects of oral potassium on blood pressure: meta-analysis of randomized controlled clinical trials. JAMA. 1997; 277:1624-32. PubMed

104. Appel LJ, Moore TJ, Obarzanek E et al for the DASH Collaborative Research Group. A clinical trial of the effects of dietary patterns on blood pressure. N Engl J Med. 1997; 336:1117-24. PubMed

105. Ryan TJ, Antman EM, Brooks NH et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction: 1999 update: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). From http://www.acc.org/clinical/guidelines and http://www.americanheart.org.

106. Diaz R, Paolasso EA, Piegas LS et al for the ECLA (Estudios Cardiologicos Latinoamerica) Collaborative Group. Metabolic modulation of acute myocardial infarction: The ECLA Glucose-Insulin-Potassium Pilot Trial. Circulation. 1998; 98:2227-34. PubMed

107. Apstein CS. Glucose-insulin-potassium for acute myocardial infarction: remarkable results from a new prospective, randomized trial. Circulation. 1998; 98:2223-6. PubMed

108. Fath-Ordoubadi F, Beatt KJ. Glucose-insulin-potassium therapy for treatment of acute myocardial infarction: an overview of randomized placebo-controlled trials. Circulation. 1997; 96:1152-6. PubMed

109. Apstein CS. Glucose-insulin-potassium in acute nyocardial infarction: the time has come for a large, prospective trial. Circulation. 1997; 96:1074-7. PubMed

110. Nordrehaug JE, von der Lippe G. Hypokalemia and ventricular fibrillation in acute myocardial infarction. Br Heart J. 1983; 50:525-9. PubMed PubMed Central

111. Higham PD, Adams PC, Murray A et al. Plasma potassium, serum magnesium and ventricular fibrillation: a prospective study. Q J Med. 1993; 86:609-17. PubMed