Alternative Therapy in Severe Hyperkalemia:
Since effective lowering of serum potassium with this product may take hours to days, treatment with this drug alone may be insufficient to rapidly correct severe hyperkalemia associated with states of rapid tissue breakdown (e.g., burns and renal failure) or hyperkalemia so marked as to constitute a medical emergency. Therefore, other definitive measures, including dialysis, should always be considered and may be imperative.
Serious potassium deficiency can occur from therapy with Kionex®. 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 Kionex® 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.
Like all cation-exchange resins, Kionex® Sodium Polystyrene Sulfonate is not totally selective (for potassium) in its actions, and small amounts of other cations such as calcium and magnesium can also be lost during treatment. Accordingly, patients receiving Kionex® should be monitored for all applicable electrolyte disturbances.
Systemic alkalosis has been reported after cation-exchange resins were administered orally in combination with nonabsorbable cation-donating antacids and laxatives such as magnesium hydroxide and aluminum carbonate. Magnesium hydroxide should not be administered with Kionex®. One case of grand mal seizure has been reported in a patient with chronic hypocalcemia of renal failure who was given sodium polystyrene sulfonate with magnesium hydroxide as laxative. (See PRECAUTIONS, Drug Interactions.)
Caution is advised when Kionex® 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 Kionex® should be discontinued until normal bowel motion is resumed. Magnesium-containing laxatives or sorbitol should not be used (see PRECAUTIONS, Drug Interactions).
The simultaneous oral administration of Kionex® with nonabsorbable cation-donating antacids and laxatives may reduce the resin's potassium exchange capability.
Non-absorbable cation-donating antacids and laxatives:
Systemic alkalosis has been reported after cation-exchange resins were administered orally in combination with nonabsorbable cation-donating antacids and laxatives such as magnesium hydroxide and aluminum carbonate. Magnesium hydroxide should not be administered with Kionex®. One case of grand mal seizure has been reported in a patient with chronic hypocalcemia of renal failure who was given sodium polystyrene sulfonate with magnesium hydroxide as a laxative.
Intestinal obstruction due to concretions of aluminum hydroxide when used in combination with sodium polystyrene sulfonate has been reported.
The toxic effects of digitalis on the heart, especially various ventricular arrhythmias and A-V nodal dissociation, are likely to be exaggerated by hypokalemia, even in the face of serum digoxin concentrations in the "normal range". (See WARNINGS.)
Concomitant use of Sorbitol with Kionex® has been implicated in cases of chronic necrosis. Therefore, concomitant administration is not recommended.
Kionex® may decrease absorption of lithium.
Kionex® may decrease absorption of thyroxine.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Studies have not been performed.
Pregnancy Category C
Animal reproduction studies have not been conducted with Kionex® (Sodium Polystyrene Sulfonate, USP). It is also not known whether Kionex® can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Kionex® should be given to a pregnant woman only if clearly needed.
It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Kionex® is administered to a nursing woman.
The effectiveness of Kionex® in pediatric patients has not been established. In neonates, Kionex® should not be given by the oral route. In both children and neonates, particular care should be observed with rectal administration, as excessive dosage or inadequate dilution could result in impaction of the resin.
Due to the risk of digestive hemorrhage or colonic necrosis, particular care should be observed in premature infants or low birth weight infants.