HalfLytely and Bisacodyl and Hyperkalemia

The use of potassium salts is contraindicated in patients with hyperkalemia, since a further increase in serum potassium concentration in such patients can lead to cardiac arrhythmias or arrest. Potassium therapy should be administered cautiously in patients with conditions predisposing to hyperkalemia, such as chronic renal failure, systemic acidosis, acute dehydration, hypoaldosteronism (e.g., due to primary adrenal insufficiency or congenital adrenal enzyme deficiency), uncontrolled diabetes mellitus, and extensive tissue breakdown (e.g., due to severe burns, intravascular hemolysis, tumor lysis syndrome, or rhabdomyolysis). Close monitoring of serum potassium concentrations is recommended, as potentially fatal hyperkalemia can develop rapidly and is often asymptomatic, manifested only by an increased potassium level (6.5 to 8 mEq/L) and characteristic electrocardiographic changes (peaking of T waves, loss of P waves, depression of ST segment, prolongation of the QT interval). Late manifestations include muscle paralysis and cardiovascular collapse from cardiac arrest (9 to 12 mEq/L). Continuous or serial electrocardiography may be appropriate in some patients during replacement therapy, particularly if given intravenously.