Kayexalate Information
Kayexalate (Sodium polystyrene sulfonate) Description
Kayexalate (Sodium polystyrene sulfonate) , brand of sodium polystyrene sulfonate is a benzene, diethenyl-polymer, with ethenylbenzene, sulfonated, sodium salt and has the following structural formula:
The drug is a cream to light brown finely ground, powdered form of sodium polystyrene sulfonate, a cation-exchange resin prepared in the sodium phase with an exchange capacity of approximately 3.1 mEq ( approximately 1 mEq) of potassium per gram. The sodium content is approximately 100 mg (4.1 mEq) per gram of the drug. It can be administered orally or in an enema.
Kayexalate (Sodium polystyrene sulfonate) Clinical Pharmacology
As the resin passes along the intestine or is retained in the colon after administration by enema, the sodium ions are partially released and are replaced by potassium ions. For the most part, this action occurs in the large intestine, which excretes potassium ions to a greater degree than does the small intestine. The efficiency of this process is limited and unpredictably variable. It commonly approximates the order of 33 percent but the range is so large that definitive indices of electrolyte balance must be clearly monitored.
Metabolic data are unavailable.
Kayexalate (Sodium polystyrene sulfonate) Indication And Usage
Kayexalate (Sodium polystyrene sulfonate) is indicated for the treatment of hyperkalemia.
Kayexalate (Sodium polystyrene sulfonate) Contraindications
Kayexalate (Sodium polystyrene sulfonate) is contraindicated in the following conditions: patients with hypokalemia, patients with a history of hypersensitivity to polystyrene sulfonate resins, obstructive bowel disease, neonates with reduced gut motility (postoperatively or drug induced) and oral administration in neonates (see ).
Kayexalate (Sodium polystyrene sulfonate) Warnings
Serious potassium deficiency can occur from therapy with Kayexalate (Sodium polystyrene sulfonate) . The effect must be carefully controlled by frequent serum potassium determinations within each 24 hour period. Since intracellular potassium deficiency is not always reflected by serum potassium levels, the level at which treatment with Kayexalate (Sodium polystyrene sulfonate) should be discontinued must be determined individually for each patient. Important aids in making this determination are the patient's clinical condition and electrocardiogram. Early clinical signs of severe hypokalemia include a pattern of irritable confusion and delayed thought processes.
Electrocardiographically, severe hypokalemia is often associated with a lengthened Q-T interval, widening, flattening, or inversion of the T wave, and prominent U waves. Also, cardiac arrhythmias may occur, such as premature atrial, nodal, and ventricular contractions, and supraventricular and ventricular tachycardias. The toxic effects of digitalis are likely to be exaggerated. Marked hypokalemia can also be manifested by severe muscle weakness, at times extending into frank paralysis.
Kayexalate (Sodium polystyrene sulfonate) Precautions
Caution is advised when Kayexalate (Sodium polystyrene sulfonate) is administered to patients who cannot tolerate even a small increase in sodium loads (i.e., severe congestive heart failure, severe hypertension, or marked edema). In such instances compensatory restriction of sodium intake from other sources may be indicated.
In the event of clinically significant constipation, treatment with Kayexalate (Sodium polystyrene sulfonate) should be discontinued until normal bowel motion is resumed. Magnesium-containing laxatives or sorbitol should not be used (see ).
The patient should be positioned carefully when ingesting the resin, in order to avoid aspiration, which may lead to bronchopulmonary complications.
Kayexalate (Sodium polystyrene sulfonate) Adverse Reactions
Kayexalate (Sodium polystyrene sulfonate) may cause some degree of gastric irritation. Anorexia, nausea, vomiting, and constipation may occur especially if high doses are given. Also, hypokalemia, hypocalcemia, and significant sodium retention, and their related clinical manifestations, may occur (see ). Occasionally diarrhea develops. Large doses in elderly individuals may cause fecal impaction (see ). Rare instances of colonic necrosis have been reported. Intestinal obstruction due to concretions of aluminum hydroxide, when used in combination with Kayexalate (Sodium polystyrene sulfonate) , has been reported.
The following events have been reported from worldwide post marketing experience:
Kayexalate (Sodium polystyrene sulfonate) Overdosage
Biochemical disturbances resulting from overdosage may give rise to clinical signs and symptoms of hypokalemia, including: irritability, confusion, delayed thought processes, muscle weakness, hyporeflexia, which may progress to frank paralysis and/or apnea. Electrocardiographic changes may be consistent with hypokalemia or hypercalcemia; cardiac arrhythmias may occur. Hypocalcemic tetany may occur. Appropriate measures should be taken to correct serum electrolytes (potassium, calcium), and the resin should be removed from the alimentary tract by appropriate use of laxatives or enemas.
Kayexalate (Sodium polystyrene sulfonate) Dosage And Administration
Suspension of this drug should be freshly prepared and not stored beyond 24 hours.
The average daily adult dose of the resin is 15 g to 60 g. This is best provided by administering 15 g (approximately 4 teaspoons) of Kayexalate (Sodium polystyrene sulfonate) one to four times daily. One gram of Kayexalate (Sodium polystyrene sulfonate) contains 4.1 mEq of sodium; one level teaspoon contains approximately 3.5 g of Kayexalate (Sodium polystyrene sulfonate) and 15 mEq of sodium. (A heaping teaspoon may contain as much as 10 g to 12 g of Kayexalate (Sodium polystyrene sulfonate) .) Since the efficiency of sodium-potassium exchange resins is approximately 33 percent, about one third of the resin's actual sodium content is being delivered to the body.
In smaller children and infants, lower doses should be employed by using as a guide a rate of 1 mEq of potassium per gram of resin as the basis for calculation.
Each dose should be given as a suspension in a small quantity of water or, for greater palatability, in syrup. The amount of fluid usually ranges from 20 mL to 100 mL, depending on the dose, or may be simply determined by allowing 3 mL to 4 mL per gram of resin.
The resin may be introduced into the stomach through a plastic tube and, if desired, mixed with a diet appropriate for a patient in renal failure.
The resin may also be given, although with less effective results, in an enema consisting (for adults) of 30 g to 50 g every six hours. Each dose is administered as a warm emulsion (at body temperature) in 100 mL of aqueous vehicle. The emulsion should be agitated gently during administration. The enema should be retained as long as possible and followed by a cleansing enema.
After an initial cleansing enema, a soft, large size (French 28) rubber tube is inserted into the rectum for a distance of about 20 cm, with the tip well into the sigmoid colon, and taped in place. The resin is then suspended in the appropriate amount of aqueous vehicle at body temperature and introduced by gravity, while the particles are kept in suspension by stirring. The suspension is flushed with 50 mL or 100 mL of fluid, following which the tube is clamped and left in place. If back leakage occurs, the hips are elevated on pillows or a knee-chest position is taken temporarily. A somewhat thicker suspension may be used, but care should be taken that no paste is formed, because the latter has a greatly reduced exchange surface and will be particularly ineffective if deposited in the rectal ampulla. The suspension is kept in the sigmoid colon for several hours, if possible. Then, the colon is irrigated with nonsodium containing solution at body temperature in order to remove the resin. Two quarts of flushing solution may be necessary. The returns are drained constantly through a Y tube connection. While the use of sorbitol is not recommended, particular attention should be paid to this cleansing enema if sorbitol has been used.
The intensity and duration of therapy depend upon the severity and resistance of hyperkalemia.
Kayexalate (Sodium polystyrene sulfonate) should not be heated for to do so may alter the exchange properties of the resin.
Kayexalate (Sodium polystyrene sulfonate) How Supplied
Kayexalate (Sodium polystyrene sulfonate) is available as a cream to light brown, finely ground powder in jars of 1 pound (453.6 g), NDC 0024-1075-01.
Kayexalate (Sodium polystyrene sulfonate)
Kayexalate (Sodium polystyrene sulfonate) Principal Display Panel - . G Jar
NDC 0024-1075-01K-450
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