Dosing and uses of Sodium phosphates IV
Adult dosage forms and strengths
Contains mixture of monobasic sodium phosphate and dibasic sodium phosphate
intravenous solution
- Phosphorus content: 93mg (3mM)/mL
- Sodium content: 92mg (4 mEq)/mL
Hypophosphatemia
The dose and administration IV infusion rate for sodium phosphates are dependent upon individual needs of the patient
Phosphorous serum level <0.5 mg/dL: 0.5 mmol/kg IV infused over 4-6 hr
Phosphorous serum level 0.5-1 mg/dL: 0.25 mmol/kg IV infused over 4-6 hr
Prevention of hypophosphatemia (eg, in TPN): 20-40 mmol/day IV admixed in TPN is typical dose, but adjustment according to electrolyte levels is ongoing
Administration
Calculate concomitant amount of sodium that will be administered: Each 1 mmol of phosphate contains ~1.3 mEq of sodium; if amount of sodium to be delivered is a concern (ie, sodium serum level >145 mEq/L), consider use of potassium phosphates IV to replete phosphorous leveL
Renal Impairment
Administration of solutions containing sodium and phosphorous in patients with impaired renal function may result in hypernatremia or hyperphosphatemia
Pediatric dosage forms and strengths
Contains mixture of monobasic sodium phosphate and dibasic sodium phosphate
intravenous solution
- Phosphorus content: 93mg (3mM)/mL
- Sodium content: 92mg (4 mEq)/mL
Hypophosphatemia
Caution should be exercised in premature neonates due to aluminum toxicity
The dose and administration IV infusion rate for sodium phosphates are dependent upon individual needs of the patient
Phosphorous serum level <0.5 mg/dL: 0.5 mmol/kg IV infused over 4-6 hr
Phosphorous serum level 0.5-1 mg/dL: 0.25 mmol/kg IV infused over 4-6 hr
Prevention of hypophosphatemia (eg, in TPN)
- Infants/children: 0.5-2 mmol/kg/day IV
- Children >50 kg or adolescents: 10-40 mmol/day IV
- Dose adjustment according to electrolyte levels is ongoing
Administration
Calculate concomitant amount of sodium that will be administered: Each 1 mmol of phosphate contains ~1.3 mEq of sodium; if amount of sodium to be delivered is a concern (ie, sodium serum level >145 mEq/L), consider use of potassium phosphates IV to replete phosphorous leveL
Renal Impairment
Administration of solutions containing sodium and phosphorous in patients with impaired renal function may result in hypernatremia or hyperphosphatemia
Sodium phosphates IV adverse (side) effects
Frequency not defined
Sodium
- Anorexia
- Nausea
- Vomiting
- Fatigue
- Irritability
- Lethargy
- Confusion
- Stupor
- Coma
- Muscle twitching
- Hyperreflexia
- Spasticity
- Tremor
- Ataxia
Phosphorus
- Hypocalcemic tetany
Warnings
Contraindications
Hyperphosphatemia
Hypocalcemia
Hypernatremia
Hypomagnesemia
Cautions
Must be diluted and thoroughly mixed before administration
Phosphorus replacement therapy with sodium phosphates should be guided primarily by the serum inorganic phosphorus levels and the limits imposed by the accompanying sodium (Na+) ion
To avoid hypernatremia or hyperphosphatemia, infuse IV solutions containing sodium phosphates slowly
Caution with severe renal or adrenal insufficiency due to risk for hypernatremia or hyperphosphatemia
Use with great care, if at all, in patients with congestive heart failure, severe renal insufficiency and in edematous conditions with sodium retention
High concentrations of phosphorus may cause hypocalcemia and hypocalcemic tetany; monitor calcium levels
Aluminum toxicity
- This product contains aluminum that may be toxic; aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired; premature neonates are at particular risk because of immature kidneys
- Aluminum doses exceeding 4-5 mcg/kg/day are associated with CNS and bone toxicity
- Tissue accumulation may occur at even lower doses
Pregnancy and lactation
Pregnancy category: C
Lactation: Unknown whether distributed in breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Sodium phosphates IV
Mechanism of action
Phosphorus is involved in many biochemical functions in the body and significant metabolic and enzyme reactions in almost all organs and tissues; it exerts a modifying influence on the steady state of calcium levels, a buffering effect on acid-base equilibrium, and a primary role in the renal excretion of hydrogen ion
Sodium is the principal cation of extracellular fluid and comprises >90% of the total cations in the body; it is critical to regulating extracellular and intravascular volume
Elimination
Excretion: feces (10%), urine (90%)
Administration
IV Incompatibilities
Calcium and phosphorous are incompatible and will precipitate in most aqueous solutions; may be mixed in some TPN admixtures in variable quantities depending on the composition of the preparation, order of mixing, pH, temperature, storage, and particular calcium salt (consult pharmacist)
Y-Site Administration
- Acyclovir, amiodarone, amphotericin B lipid complex (Abelcet), amphotericin B liposome (AmBisome), anidulafungin, caspofungin, ciprofloxacin, daunorubicin liposome, doripenem, doxacurium, doxorubicin, epirubicin, gemtuzumab ozogamicin, idarubicin, ifosfamide, ketamine, lansoprazole, leucovorin calcium, lorazepam, mitoxantrone, mycophenolate, pantoprazole, quinupristin/dalfopristin, rocuronium
Admixture
- Ciprofloxacin, dobutamine
Syringe
- Aminophylline, pantoprazole, salbutamol
For Dilution
- D10% in 0.9% NaCl; D2.5% in Half-strength LR; D5% in LR; Dextrose 5% in Ringer's; Lactated Ringer's; Ringer's injection
IV Compatibilities
Y-Site Administration
- Alemtuzumab, aminocaproic acid, argatroban, atenolol, bivalirudin, bleomycin, carboplatin, carmustine, cisplatin, cyclophosphamide, cytarabine, dactinomycin, daptomycin, dexmedetomidine, dexrazoxane, diltiazem
Admixture
- Magnesium sulfate, metoclopramide, verapamil
For Dilution
- Dextran 70 6% in D5W; dextran 70 6% in 0.5% NaCl; D10W; D2.5W; D2.5/0.45% NaCl; D5/0.2% NaCl; D5/0.45% NaCl; D5/NS; 0.9% NaCl (NS); 0.45% NaCl; sodium lactate 1/6 M
IV Administration
Administered IV only after dilution in a larger volume of fluid
Administer slowly over 4-6 hr
Storage
Store at 20- 25°C (68- 77°F); excursions permitted to 15-30°C (59-86°F)
Does not contain a bacteriostatic agent or other preservatives; discard any unused portion
