sodium phosphate

Therapeutic Classification: mineral and electrolyte replacements/supplements

Pharmacologic Classification: phosphate supplements

Indications ⬆ ⬇

REMS

Treatment and prevention of phosphate depletion in patients who are unable to ingest adequate dietary phosphates.

Action ⬆ ⬇

Phosphate is present in bone and is involved in energy transfer and carbohydrate metabolism.
Serves as a buffer for the excretion of hydrogen ions by the kidney.

Therapeutic effects:

Replacement of phosphorus in deficiency states.

Pharmacokinetics ⬆ ⬇

Absorption: Administered IV only, resulting in complete bioavailability.

Distribution: Phosphates enter extracellular fluids and are then actively transported to sites of action.

Metabolism/Excretion: Excreted mainly (>90%) by the kidneys.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(effects on serum phosphate levels)

ROUTE	ONSET	PEAK	DURATION
IV	rapid (min–hr)	end of infusion	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hyperphosphatemia;
Hypocalcemia;
Severe renal impairment.

Use Cautiously in:

Hyperparathyroidism;
Cardiac disease;
Hypernatremia;
Hypertension.

Adv. Reactions/Side Effects ⬆ ⬇

Related to hyperphosphatemia, unless otherwise indicated

CV: ECG changes (absent P waves, widening of the QRS complex with biphasic curve), ARRHYTHMIAS, CARDIAC ARREST, hypotension; hypernatremia: edema

F and E: hyperkalemia, hypernatremia, hyperphosphatemia, hypocalcemia, hypomagnesemia

GI: diarrhea, abdominal pain, nausea, vomiting

Local: irritation at IV site, phlebitis

MS: hypocalcemia: tremors

Neuro: confusion, flaccid paralysis, heaviness of legs, listlessness, paresthesias of extremities, weakness

Resp: hypernatremia: shortness of breath

Interactions ⬆ ⬇

Drug-drug:

Concurrent use ofcorticosteroids with sodium phosphate may result in hypernatremia.

Route/Dosage ⬆ ⬇

IV (Adults ): 12–15 mmol phosphorus/liter of parenteral nutrition.
IV (Children ): Hypophosphatemia: 0.08–0.36 mmol/kg over 6 hrs;Maintenance: <25 kg: 0.5–1.5 mmol/kg/day; 25–45 kg: 0.5–1 mmol/kg/day.
IV (Neonates ): Maintenance: 0.8–1.5 mmol/kg/day (infused as part of parenteral nutrition).

Availability ⬆ ⬇

(Generic available)

IV injection for dilution: 3 mmol phosphate and 4 mEq sodium/mL in 10-, 15-, 30-, and 50-mL vials

Assessment ⬆ ⬇

Assess patient for signs and symptoms of hypophosphatemia (anorexia, weakness, decreased reflexes, bone pain, confusion, blood dyscrasias) throughout therapy.
Monitor intake and output ratios and daily weight. Report significant discrepancies.

Lab Test Considerations:

Monitor serum phosphate, potassium, sodium, and calcium levels prior to and periodically throughout therapy. Increased phosphate may cause hypocalcemia.
- Monitor renal function studies prior to and periodically throughout therapy.

Toxicity and Overdose:

Symptoms of toxicity are those of hyperphosphatemia or hypocalcemia (paresthesia, muscle twitching, laryngospasm, colic, cardiac arrhythmias, Chvostek’s or Trousseau’s signs) or hypernatremia (thirst; dry, flushed skin; fever; tachycardia; hypotension; irritability; decreased urine output).

Implementation ⬆ ⬇

Available in oral form in combination with potassium phosphate to acidify urine and to prevent formation of renal calculi (see Potassium and Sodium Phosphates monographs).
IV: Administer IV only in dilute concentrations and infuse slowly over 4–6 hr.
Y-Site Compatibility:
Y-Site Incompatibility:
- ciprofloxacin
Additive Incompatibility:
- calcium
- magnesium

IV Administration:

Diluent: Dilute with 0.45% NaCl, 0.9% NaCl, D5W, D10W, D5/0.45% NaCl, D5/0.9% NaCl, or TPN solutions.Concentration: Peripheral line maximum: 0.05 mmol/mL; Central line maximum: 0.12 mmol/mL.
Rate: Maximum rate: 0.06 mmol/kg/hr.

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Pronunciation ⬇

Classifications ⬆ ⬇