Potassium phosphate

You should not use potassium phosphate if you have low levels of calcium, or high levels of potassium or phosphorus in your body.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

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• K-Phos

Injection: Hyperphosphatemia, hyperkalemia, hypocalcemia

Oral: Severe renal impairment (<30% of normal function); hyperkalemia, hyperphosphatemia; infected phosphate stones

Refer to adult dosing.

ACE Inhibitors: Potassium Salts may enhance the hyperkalemic effect of ACE Inhibitors. Monitor therapy

Aliskiren: Potassium Salts may enhance the hyperkalemic effect of Aliskiren. Monitor therapy

Alpha-/Beta-Agonists (Indirect-Acting): Urinary Acidifying Agents may decrease the serum concentration of Alpha-/Beta-Agonists (Indirect-Acting). Monitor therapy

Amantadine: Urinary Acidifying Agents may decrease the serum concentration of Amantadine. Monitor therapy

Amphetamines: Urinary Acidifying Agents may decrease the serum concentration of Amphetamines. Monitor therapy

Angiotensin II Receptor Blockers: Potassium Salts may enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Monitor therapy

Antacids: May decrease the serum concentration of Potassium Phosphate. Management: Consider separating administration of antacids and oral potassium phosphate by at least 2 hours to decrease risk of a significant interaction. Consider therapy modification

Calcium Salts: May decrease the absorption of Phosphate Supplements. Management: This applies only to oral phosphate and calcium administration. Administering oral phosphate supplements as far apart from the administration of an oral calcium salt as possible may be able to minimize the significance of the interaction. Consider therapy modification

ChlorproPAMIDE: Urinary Acidifying Agents may increase the serum concentration of ChlorproPAMIDE. Monitor therapy

Eplerenone: May enhance the hyperkalemic effect of Potassium Salts. Management: This combination is contraindicated in patients receiving eplerenone for treatment of hypertension. Consider therapy modification

Heparin: May enhance the hyperkalemic effect of Potassium Salts. Monitor therapy

Heparin (Low Molecular Weight): May enhance the hyperkalemic effect of Potassium Salts. Monitor therapy

Iron Salts: May decrease the absorption of Phosphate Supplements. Management: This applies only to oral phosphate and iron administration. Administer oral phosphate supplements at least 1 hour before, or 2 hours after, oral iron salt administration. Exceptions: Ferric Carboxymaltose; Ferric Gluconate; Ferric Hydroxide Polymaltose Complex; Ferric Pyrophosphate Citrate; Ferumoxytol; Iron Dextran Complex; Iron Sucrose. Consider therapy modification

Magnesium Salts: May decrease the serum concentration of Phosphate Supplements. Management: This applies only to oral phosphate and magnesium administration. Administer oral phosphate supplements at least 1 hour before, or 2 hours after, oral magnesium salt administration. Consider therapy modification

Mecamylamine: Urinary Acidifying Agents may decrease the serum concentration of Mecamylamine. Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): May decrease the serum concentration of Phosphate Supplements. Management: This applies only to oral phosphate and multivitamin administration. Administer oral phosphate supplements at least 1 hour before, or 2 hours after, administration of an iron-containing multivitamin. Consider therapy modification

Nicorandil: May enhance the hyperkalemic effect of Potassium Salts. Monitor therapy

Potassium-Sparing Diuretics: Potassium Salts may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Consider therapy modification

Salicylates: Potassium Phosphate may increase the serum concentration of Salicylates. Monitor therapy

Sucralfate: May decrease the absorption of Phosphate Supplements. Management: This applies only to oral phosphate administration. Administering oral phosphate supplements at least 1 hour before or 2 hours after administration of sucralfate may reduce the significance of the interaction. Consider therapy modification

Concerns related to adverse effects:

• Extravasation: Vesicant/irritant (may depend on concentration); ensure proper catheter or needle position prior to and during infusion. Avoid extravasation.

• Hyperkalemia: Close monitoring of serum potassium concentrations is needed to avoid hyperkalemia; severe hyperkalemia may lead to muscle weakness/paralysis and cardiac conduction abnormalities (eg, heart block, ventricular arrhythmias, asystole).

• Laxative effect: A mild laxative effect may occur with oral use within the first few days of therapy; if the laxative effect persists to a self-limiting degree, consider reducing the dose or discontinue use until diarrhea improves.

Disease-related concerns:

• Acid/base disorders: Use with caution in patients with acid/base alterations; changes in serum potassium concentrations can occur during acid/base correction, monitor closely.

• Adrenal insufficiency: Use with caution in patients with adrenal insufficiency (eg, Addison disease); adrenal insufficiency requires close monitoring of serum potassium and phosphorus concentrations to avoid hyperkalemia and/or hyperphosphatemia.

• Cardiovascular disease: Use with caution in patients with cardiovascular disease (eg, heart failure, cardiac arrhythmias); patients may be more susceptible to life-threatening cardiac effects associated with hyper/hypokalemia.

• Dehydration: Use with caution in patients with acute dehydration.

• Myotonia congenita: Use with caution in patients with myotonia congenita.

• Pancreatitis: Use with caution in patients with acute pancreatitis.

• Parathyroid disease: Use with caution in patients with hypoparathyroidism.

• Renal calculi: Patients with renal calculi may pass preformed stones when phosphate therapy is initiated.

• Renal impairment: Use with caution in patients with renal impairment; renal impairment requires close monitoring of serum potassium and phosphorus concentrations to avoid hyperkalemia and/or hyperphosphatemia. Oral tablets are contraindicated in patients with severe renal impairment.

• Rickets: Use with caution in patients with rickets; may increase the risk of extraskeletal calcification.

• Tissue breakdown: Use with caution in patients with extensive tissue breakdown (eg, severe burns).

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Dosage form specific issues:

• Aluminum: The parenteral product may contain aluminum; toxic aluminum concentrations may be seen with high doses, prolonged use, or renal dysfunction. Premature neonates are at higher risk due to immature renal function and aluminum intake from other parenteral sources. Parenteral aluminum exposure of >4 to 5 mcg/kg/day is associated with CNS and bone toxicity; tissue loading may occur at lower doses (Federal Register 2002). See manufacturer's labeling.

• Oral administration: Tablets should be dissolved completely in water prior to administration to avoid GI injury due to administration of a concentrated potassium salt preparation.

• Parenteral administration: Use extreme caution when administering potassium phosphate parenterally; evaluate patient's renal function, cardiac and fluid status, and any factors contributing to altered potassium concentrations (eg, acidosis, alkalosis) prior to therapy. Closely monitor potassium and phosphate concentrations and response to therapy. Parenteral potassium may cause pain and phlebitis, requiring a decrease in infusion rate or potassium concentration.

Other warnings/precautions:

• Calcium/phosphate compatibility: Admixture of phosphate and calcium in IV fluids can result in calcium phosphate precipitation.

IV: Serum potassium, calcium, phosphorus, magnesium (to facilitate potassium repletion); cardiac monitor (if intermittent infusion or potassium infusion rates >0.5 mEq/kg/hour in children or >10 mEq/hour in adults); to assess adequate replacement, repeat serum potassium and phosphorus levels 2 to 4 hours after dose; renal function

Oral: Serum potassium, phosphorus, and calcium; renal function; serum salicylate concentration (in patients taking concomitant salicylates)