Treatment or prevention of hypokalemia (potassium deficiency) in patients in whom dietary measures are inadequate.
Conditions that 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 that 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.
Potassium replacement may be indicated in patients receiving certain drugs that may sometimes cause potassium depletion (e.g., thiazide diuretics, carbonic anhydrase inhibitors, loop diuretics, some corticosteroids, corticotropin, aminosalicylic acid, amphotericin B). Although ingestion of potassium-rich foods and/or use of potassium-containing salt substitutes may prevent potassium depletion in patients receiving potassium-depleting drugs, judicious prophylactic administration of potassium may be advisable in selected patients during prolonged diuretic or corticosteroid therapy, especially if they are digitalized.
Potassium chloride usually is the salt of choice in the treatment of potassium depletion, since the chloride ion is required to correct hypochloremia which frequently accompanies potassium deficiency and since the citrate, bicarbonate, gluconate, or another alkalinizing salt of potassium may cause hypochloremia, particularly when used in conjunction with chloride-restricted diets.
Potassium also is available as the potassium phosphate salt; however, potassium phosphate usually is used to replace phosphate losses or to correct coexisting hypokalemia and hypophosphatemia.For further information on potassium phosphate, see Phosphates.
Hypertension
Inadequate dietary intake of potassium plays an important role in the development of hypertension, and high dietary intake of potassium (including use of potassium supplements) may protect against the development of high blood pressure and improve blood pressure control in patients with hypertension.
Most experts recommend that an adequate intake of potassium (about 50–90 mEq daily) be maintained in hypertensive patients as part of lifestyle modifications, particularly in those unable to adequately reduce their sodium intake.
Adequate intake of potassium should be considered as a means of preventing the development of hypertension. Food sources high in potassium such as fruits and vegetables are preferred. Alternatively, potassium supplements or salt-substitutes or potassium-sparing diuretics can be used, particularly in patients receiving kaliuretic diuretics.
AMI
Potassium supplementation, combined with magnesium supplementation if necessary, has been used to reduce risk of ventricular arrhythmias in patients with AMI.
Clinical experience as well as observational data from coronary care unit populations indicate that hypokalemia is a risk factor for development of ventricular fibrillation. Although benefits of potassium supplementation as a strategy in preventing ventricular fibrillation following AMI have not been confirmed, maintaining serum potassium and magnesium concentrations at levels >4 and >2 mEq/L, respectively, is considered sound clinical practice.
IV potassium chloride has been used early in the course of suspected AMI† in conjunction 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.
Initial experience (from the pre-thrombolytic reperfusion era) with early post-MI GIK therapy indicate substantial potential reductions in mortality associated with AMI. Pooled analysis of early studies indicate an overall mortality reduction benefit of 28–48%, which depended on the dosage and timing of GIK therapy relative to symptom onset.
GIK therapy appears to be a feasible strategy in the early hours after an AMI.
Arrhythmias
Potassium salts may be used cautiously to abolish arrhythmias of cardiac glycoside toxicity precipitated by a loss of potassium.
Elevation of plasma potassium concentrations by 0.5–1.5 mEq/L or to the ULN may be useful in the management of tachyarrhythmias following cardiac surgery, but this strategy should not be used in patients with atrioventricular block since potassium may further impair nodal conduction.
Thallium Toxicity
IV potassium supplements, usually potassium chloride, have been used in the management of thallium poisoning† to enhance diuresis and mobilize thallium from tissues; such treatment is limited by the amount of thallium that can be released into the blood without worsening cerebral symptoms.
Dosage and Administration
Administration
Administer orally or by slow IV infusion. Potassium-containing injections (usually potassium chloride), have been administered by hypodermoclysis† (into subcutaneous tissues).
Potassium acetate, bicarbonate, chloride, citrate, and gluconate can be administered orally. Potassium acetate and chloride can be administered IV.
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. Replace IV potassium therapy with oral supplements and/or ingestion of potassium-rich foods as soon as possible.
Oral Administration
Oral potassium supplements should preferably be administered 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.
Usually administered orally in 1–4 doses daily. Daily dosage >20 mEq should be divided into several doses and should not be given as a single dose.
Powders or tablets for oral solution should be dissolved and/or diluted and administered according to the manufacturers’ directions.
Extended-release potassium chloride preparations should be reserved for use in 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.
IV Infusion
Close monitoring of ECG and plasma potassium concentrations is essential during IV administration of potassium, especially when the rate of administration is >20 mEq/hour. (See Hyperkalemia under Cautions.)
Potassium IV solutions should generally be administered only in patients with adequate urine flow (e.g., administer to postoperative patients only after adequate urine flow established).
In dehydrated patients, 1 liter of potassium-free fluid should be administered prior to initiating potassium therapy.
Local vascular intolerance may limit the ability to administer concentrated solutions; administer via large, high-flow vein (e.g., femoral vein) or administer less concentrated solutions in divided doses via 2 veins simultaneously. Avoid administration of concentrated potassium solutions via subclavian, jugular, or right atrial catheter; local potassium concentrations achieved in the heart may be high and potentially cardiotoxic.
Potassium chloride 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.
Hyperkalemia has been reported when concentrated potassium chloride solutions were added to IV 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 does not facilitate mixing but tends to pump the concentrated solution into the infusion chamber. Such solutions must be carefully mixed by inverting the plastic container during the addition of potassium solutions with subsequent agitation and/or kneading to prevent pooling.
Dilution
For solution and drug compatibility information, see Compatibility under Stability.
Potassium acetate and potassium chloride are available as concentrates that must be diluted prior to IV administration.
Generally, potassium concentrations in IV fluids should not exceed 40 mEq/L. However, higher potassium concentrations (e.g., 60–80 mEq/L) occasionally may be needed initially for management of severe hypokalemia and associated cardiac arrhythmias, diabetic ketoacidosis or diuretic phase of acute renal failure.
Rate of Administration
Must be administered by slow IV infusion. Generally, rate of administration should not exceed 20 mEq/hour.
More rapid administration occasionally may be necessary for management of severe hypokalemia and associated cardiac arrhythmias or diabetic ketoacidosis or diuretic phase of acute renal failure.
Hypodermoclysis
If administered by hypodermoclysis†, potassium concentrations should not exceed 10 mEq/L to avoid local pain.
Dosage
Dosage of potassium supplements usually expressed as mEq of potassium.
Normal adult daily potassium requirement and usual dietary intake of potassium is 40–80 mEq; infants may require 2–3 mEq/kg or 40 mEq/m2 daily.
Dosage must be carefully individualized according to the patient’s requirements and response.
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 replacement requirements can be estimated only by clinical condition and response, ECG monitoring, and/or plasma potassium determinations.
If used in pediatric patients†, do not exceed 3 mEq/kg daily in young children.†
Adults
Hypokalemia
Prevention
Oral
Average dosage approximately 20 mEq daily. Usually should not exceed 200 mEq daily.
Treatment
Oral
Usual dosage is 40–100 mEq or more daily. Usually should not exceed 200 mEq daily.
AMI
Glucose-Insulin-Potassium (GIK) Therapy
IV
GIK therapy in AMI patients involves use of IV potassium chloride in conjunction with IV insulin injection (regular insulin) and IV dextrose (D-glucose). Goal is to maintain serum potassium concentrations >4 mEq/L and serum magnesium concentrations >2 mEq/L.†
Low-dose regimen: IV solution containing potassium chloride 40 mEq/L, 10% dextrose, and 20 units insulin [regular]/L given at a rate of 1 mL/kg per hour per 24 hours.†
High-dose regimen: IV solution containing potassium chloride 80 mEq/L, 25% dextrose, and 50 units insulin [regular]/L given at a rate of 1.5 mL/kg per hour for 24 hours.†
Usually initiated in AMI patients within approximately 10–11 hours of symptom onset. Both low-dose and high-dose regimens appear beneficial; some evidence suggests that the high-dose regimen may be more effective.†
Prescribing Limits
Pediatric Patients
Hypokalemia
Prevention or Treatment
Oral
3 mEq/kg daily for young children.†
Adults
Hypokalemia
Prevention or Treatment
Oral
Usually should not exceed 200 mEq daily.
Special Populations
Renal Impairment
Cautious dosage selection and careful monitoring recommended in patients with renal impairment.
Geriatric Patients
Select dosage with caution, starting at low end of dosage range, because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.
Cautions
Contraindications
Hyperkalemia, including that complicating chronic renal failure, systemic acidosis (e.g., diabetic acidosis), acute dehydration, extensive tissue breakdown (e.g., in severe burns), adrenal insufficiency, or concomitant use of potassium-sparing diuretics (e.g., amiloride, spironolactone, triamterene).
Severe renal impairment with oliguria, anuria, or azotemia.
Use of solid oral dosage preparations in patients with structural, pathologic (e.g., diabetic gastroparesis), and/or pharmacologic (e.g., induced by anticholinergic agents) causes for arrest or delay in GI transit.
Use of extended-release preparations in patients with esophageal compression caused by an enlarged left atrium.
Warnings/Precautions
Warnings
Hyperkalemia
Hyperkalemia and cardiac arrest can occur following use of potassium supplements in patients with impaired mechanisms for excreting potassium. Most common and serious adverse effect of potassium therapy.
Potentially fatal; can develop rapidly and patients may be asymptomatic. Occurs most frequently with IV potassium (especially if administered too rapidly), but may occur with oral potassium.
Use IV solutions containing potassium with extreme caution, if at all, in patients with hyperkalemia, severe renal failure, or other conditions with potassium retention.
Evaluate renal function before therapy; monitor clinical status with periodic ECGs and/or determinations of plasma potassium concentrations.
Clinical signs and symptoms of hyperkalemia 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.
Metabolic Acidosis
In patients who have both hypokalemia and metabolic acidosis, an alkalinizing potassium salt (acetate, bicarbonate, citrate, gluconate) should be used for treatment of hypokalemia.
Fluid Overload and Edematous States
Use of IV solutions containing potassium may cause fluid and/or solute overload, leading to decreased electrolyte concentrations, overhydration, congestion, and pulmonary edema.
Use IV solutions containing potassium with extreme caution, if at all, in patients with CHF, severe renal insufficiency, or other conditions with sodium retention and edema.
GI Lesions
Solid oral dosage forms of potassium have resulted in ulcerative and/or stenotic GI lesion; perforation has occurred. Possibly more frequent with enteric-coated tablets (no longer commercially available in the US).
Administer wax matrix and extended-release preparations with caution; discontinue immediately if abdominal pain, distention, severe vomiting, or GI bleeding occurs.
Reserve use of extended-release potassium chloride preparations 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.
Some experts question the use of any solid potassium preparation, since use of dilute liquid preparations minimizes the risk of GI complications.
Local Reactions
Pain and phlebitis may occur at IV administration site, especially with potassium solutions containing ≥30 mEq/L.
General Precautions
Laboratory Monitoring
Monitor fluid balance, electrolyte concentrations, and acid-base balance periodically during therapy. Regular serum potassium determinations are recommended, especially in patients with renal impairment or diabetic nephropathy.
Use of Parenteral Solutions
When potassium is administered IV in parenteral solutions, consider the cautions, precautions, and contraindications associated with fluid volume and electrolytes contained in the IV infusion fluid.
Specific Populations
Pregnancy
Category C.
Lactation
Not known whether potassium is distributed into milk. Use with caution.
Pediatric Use
Safety and efficacy not established.
Geriatric Use
Response in patients ≥65 years of age does not appear to differ from that in younger adults; however, use with caution due to greater frequency of decreased hepatic, renal, and/or cardiac function and of concomitant disease and drug therapy observed in the elderly.
Monitor renal function.
Renal Impairment
Parenteral solutions containing potassium may cause sodium and/or potassium retention.
Use cautiously; monitor plasma potassium concentrations frequently.
Common Adverse Effects
Hyperkalemia; GI effects (nausea, vomiting, diarrhea, flatulence, abdominal pain or discomfort); infusion site reactions.
Following oral administration of extended-release formulations, potassium is released slowly; risk of high, localized concentrations is minimized.
Plasma Concentrations
Normal plasma potassium concentrations generally range from 3.5–5 mEq/L in healthy adults.
Plasma concentrations up to 7.7 mEq/L may be normal in neonates.
Plasma potassium concentrations are not necessarily indicative of cellular potassium concentrations; cellular deficits may occur without concomitant decreases in plasma potassium concentrations. Hypokalemia may occur without substantial depletion of cellular potassium.
Extracellular fluid pH changes produce reciprocal effects on plasma potassium concentrations; 0.1 unit increase in plasma pH produces a decrease of 0.6 mEq/L in plasma potassium concentration.
Distribution
Extent
Enters extracellular fluid and actively transported into cells; intracellular concentration is up to 40 times extracellular concentration.
Intracellular movement augmented by dextrose, insulin, and oxygen.
Potassium concentrations in gastric and intestinal secretions are higher than plasma concentrations; diarrheal fluid may contain up to 60 mEq/L.
Elimination
Elimination Route
Excreted principally in urine; small amounts may be excreted via the skin and intestinal tract.
Filtered by the glomeruli, reabsorbed in the proximal tubule, and secreted in the distal tubule, the site of sodium-potassium exchange.
Tubular secretion influenced by chloride ion concentration, hydrogen ion exchange, acid-base equilibrium, and adrenal hormones.
Healthy adults on potassium-free diets usually excrete 40–50 mEq of potassium daily.
Special Populations
Potassium excretion decreased in patients with renal impairment.
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.
Stability
Storage
Oral
Capsules and Tablets
Tight, light resistant containers at 15–30°C.
Powder for Solution
15–30°C.
Solution
15–30°C.
Parenteral
Injection for IV Infusion
25°C (may be exposed to 15–30°C).
Concentrate For IV Infusion
25°C (may be exposed to up to 40°C).
Compatibility
For information on systemic interactions resulting from concomitant use, see Interactions.
The major cation of intracellular fluid; essential for maintenance of acid-base balance, isotonicity, and electrodynamic cellular function.
Important activator in many enzymatic reactions; essential for transmission of nerve impulses; contraction of cardiac, smooth, and skeletal muscles; gastric secretion; renal function; tissue synthesis; and carbohydrate metabolism.
Reduces mean SBP and DBP.
Mechanism of beneficial effect of metabolic modulation with potassium in combination with dextrose (D-glucose) and insulin (glucose-insulin-potassium or GIK therapy) following an AMI has not been completely determined.
Current evidence suggests that several metabolic mechanisms may be involved in the protective effects of GIK on ischemic myocardium.
GIK decreases both circulating concentrations of free fatty acids (FFAs) and myocardial uptake of FFAs shown to be toxic to ischemic myocardium.
Stimulates myocardial potassium uptake by insulin via Na+-K+-ATPase and provision of glucose (substrate) for glycolic ATP production.
Advice to Patients
Importance of advising patient to take oral supplement with meal and full glass of water.
Importance of taking only as prescribed; do not increase dosage or duration of therapy unless otherwise instructed by a clinician.
Importance of informing clinician of tarry stools or other GI symptoms.
Importance of informing clinician of difficulty swallowing capsules or if capsules seem to become stuck in throat.
Advise patient to swallow capsules and not crush, chew, or suck capsules.
Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.
Importance of women informing their clinician if they are or plan to become pregnant or plan to breast-feed.
Importance of informing patients of other important precautionary information. (See Cautions.)
Preparations
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name
Comparative Pricing
This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 09/2009. For the most current and up-to-date pricing information, please visit www.drugstore.com. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.
† Use is not currently included in the labeling approved by the US Food and Drug Administration.
Remember, keep this and all other medicines out of the reach of children,
never share your medicines with others, and use this medication only for the indication prescribed.
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