Sodium Phosphate, Monobasic, Monohydrate

Sodium Phosphates Injection, USP is indicated as a source of phosphate, for addition to large volume intravenous fluids, to prevent or correct hypophosphatemia in patients with restricted or no oral intake. It is also useful as an additive for preparing specific parenteral fluid formulas when the needs of the patient cannot be met by standard electrolyte or nutrient solutions. The concomitant amount of sodium (4 mEq/mL) must be calculated into total electrolyte dose of such prepared solutions.

Sodium phosphate is contraindicated in diseases where high phosphate or low calcium levels may be encountered, and in patients with hypernatremia.

WARNING: 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 particularly at risk because their kidneys are immature, and they require large amounts of calcium and phosphate solutions, which contain aluminum. Research indicates that patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum at greater than 4 to 5 mcg/kg/day accumulate aluminum at levels associated with central nervous system and bone toxicity. Tissue loading may occur at even lower rates of administration. Sodium Phosphates Injection must be diluted and thoroughly mixed before use. To avoid phosphate intoxication, infuse solutions containing sodium phosphate slowly. Infusing high concentrations of phosphate may result in a reduction of serum calcium and symptoms of hypocalcemic tetany. Calcium levels should be monitored. Solutions containing sodium ion should be used with great care, if at all, in patients with congestive heart failure, severe renal insufficiency and in clinical states in which there exists edema with sodium retention. In patients with diminished renal function, administration of solutions containing sodium ions may result in sodium retention.

General Use with caution in patients with renal impairment, cirrhosis, cardiac failure or in conjunction with other edematous medications. It should not be used with sodium-retaining medications. Caution must be exercised in the administration of parenteral fluids especially those containing sodium ion, to patients receiving corticosteroids or corticotropin. Laboratory Tests Phosphate replacement therapy with sodium phosphate should be guided primarily by serum inorganic phosphate levels and the limits imposed by the accompanying sodium (Na + ) ion. Frequent monitoring of serum calcium and sodium as well as renal function is recommended. Drug Interactions Concurrent use with thiazides may cause renal damage. Pregnancy Category C Animal reproduction studies have not been conducted with sodium phosphate. It is also not known whether sodium phosphate can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Sodium phosphate should be given to a pregnant woman only if clearly needed. Nursing Mothers 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 sodium phosphate is administered to a nursing woman. Geriatric Use An evaluation of current literature revealed no clinical experience identifying differences in response between elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Sodium ions and phosphorus ions are known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

General Use with caution in patients with renal impairment, cirrhosis, cardiac failure or in conjunction with other edematous medications. It should not be used with sodium-retaining medications. Caution must be exercised in the administration of parenteral fluids especially those containing sodium ion, to patients receiving corticosteroids or corticotropin.

Laboratory Tests Phosphate replacement therapy with sodium phosphate should be guided primarily by serum inorganic phosphate levels and the limits imposed by the accompanying sodium (Na + ) ion. Frequent monitoring of serum calcium and sodium as well as renal function is recommended.

Drug Interactions Concurrent use with thiazides may cause renal damage.

Pregnancy Category C Animal reproduction studies have not been conducted with sodium phosphate. It is also not known whether sodium phosphate can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Sodium phosphate should be given to a pregnant woman only if clearly needed.

Nursing Mothers 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 sodium phosphate is administered to a nursing woman.

Geriatric Use An evaluation of current literature revealed no clinical experience identifying differences in response between elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Sodium ions and phosphorus ions are known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Adverse reactions involve the possibility of phosphate intoxication. Phosphate intoxication results in a reduction of serum calcium and the symptoms are those of hypocalcemic tetany (see WARNINGS ).