Phosphates (Systemic)

This monograph includes information on the following:

1) Potassium Phosphates
2) Potassium and Sodium Phosphates
3) Sodium Phosphates  

VA CLASSIFICATION
Primary: TN408
Secondary: GU900

Commonly used brand name(s): K-Phos M. F2; K-Phos Neutral2; K-Phos No. 22; K-Phos Original1; Neutra-Phos2; Neutra-Phos-K1; NeutraPhos2; Uro-KP-Neutral2.

Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).

Not commercially available in Canada.



Category:


Acidifier (urinary)—Monobasic Potassium Phosphate; Potassium and Sodium Phosphates;

Antiurolithic (calcium calculi)—Monobasic Potassium Phosphate; Potassium and Sodium Phosphates;

Electrolyte replenisher—Potassium Phosphates; Potassium and Sodium Phosphates; Sodium Phosphates;

Indications

Accepted

Hypophosphatemia (prophylaxis and treatment)—Phosphates, both oral and parenteral, provide supplemental ionic phosphorus for correction of hypophosphatemia in patients with low or restricted oral intake or conditions with increased requirements for phosphorus, {01} such as premature infants fed human milk, {11} {12} or patients who have inadequately controlled diabetes mellitus, {14} {16} {19} hyperparathyroidism, {16} hyperthyroidism, {16} {19} chronic alcoholism, {14} {19} renal tubular defects leading to increased urinary phosphate loss, {14} {16} respiratory alkalosis, {19} gastrectomy, {19} vitamin D deficiency, {16} {19} total parenteral nutrition (TPN) therapy, {14} {16} {19} or patients who use thiazide diuretics, {01} {19} {20} intravenous dextrose solutions, {19} {20} {21} or those who chronically use aluminum- or magnesium-containing antacids {11}. For prophylaxis of phosphorus deficiency, dietary improvement, rather than supplementation, is advisable. For treatment of phosphorus deficiency, supplementation is preferred. {50}
—Requirements for all vitamins and most minerals are increased during pregnancy. Many physicians recommend that pregnant women receive multivitamin and mineral supplements, especially those pregnant women who do not consume an adequate diet and those in high-risk categories (i.e., women carrying more than one fetus, heavy cigarette smokers, and alcohol and drug abusers). {47} Taking excessive amounts of a multivitamin and mineral supplement may be harmful to the mother and/or fetus and should be avoided.
—Recommended intakes for all vitamins and most minerals are increased during breast-feeding. {11}

Urinary tract infections (treatment adjunct)—Urinary acidification by potassium and sodium phosphates combination and monobasic potassium phosphate augments the efficacy of methenamine mandelate and methenamine hippurate, which are dependent upon an acid medium for antibacterial activity. Phosphates eliminate the odor, rash, and turbidity present with ammoniacal urine associated with urinary tract infections. {07} {08} However, use of phosphates for urea splitting urinary tract infections may predispose to struvite stones that form in alkaline urine. {44}

Renal calculi, calcium (prophylaxis)—Potassium and sodium phosphates combination and monobasic potassium phosphate have been used to reduce urinary calcium concentration and help prevent precipitation of calcium deposits in the urinary tract. {22} {23}

Unaccepted
Although sodium and/or potassium phosphates have been used in the treatment of hypercalcemia, USP medical advisory panels do not recommend this use since these medications have been replaced by safer and more effective agents.


Pharmacology/Pharmacokinetics

Physicochemical characteristics:
Molecular weight—
    Dibasic potassium phosphate: 174.18 {48}
    Dibasic sodium phosphate (heptahydrate): 268.07 {48}
    Monobasic potassium phosphate: 136.09 {48}
    Monobasic sodium phosphate (anhydrous): 119.98

Mechanism of action/Effect:

Urinary acidification—At the renal distal tubule, the secretion of hydrogen by the tubular cell in exchange for sodium in the tubular urine converts dibasic phosphate salts to monobasic phosphate salts. Therefore, large amounts of acid can be excreted without lowering the pH of the urine to a degree that would block hydrogen transport by a high concentration gradient between the tubular cell and luminal fluid.

Antiurolithic—Phosphates inhibit spontaneous nucleation of calcium oxalate, thus reducing the possibility of calcium urolithiasis. {22} {26} {27}

Electrolyte replenisher—Phosphorus modifies the steady state of calcium concentrations, has a buffering effect on acid-base equilibrium, and influences the renal excretion of hydrogen ion. {01}

Absorption:

Ingested phosphates are absorbed from the gastrointestinal tract. However, the presence of large amounts of calcium or aluminum {11} may lead to formation of insoluble phosphate and reduce the net absorption. Vitamin D stimulates phosphate absorption.

Elimination:
    Renal (90%) and fecal (10%).


Precautions to Consider

Pregnancy/Reproduction

Pregnancy—
Adequate and well-controlled studies have not been done in humans. {01} {07} However, problems in humans have not been documented with intakes of normal daily recommended amounts.

Studies have not been done in animals. {01} {07}

FDA Pregnancy Category C.

Breast-feeding

It is not known if phosphates are distributed into breast milk. However, problems in nursing infants have not been documented with intake of normal daily recommended amounts.

Pediatrics

Problems in pediatrics have not been documented with intake of normal daily recommended amounts. However, there have been several case reports of phosphate toxicity in pediatric patients from use of phosphate-containing enemas. {42} {43}.


Geriatrics


Problems in geriatrics have not been documented with intakes of normal daily recommended amounts.

Drug interactions and/or related problems
The following drug interactions and/or related problems have been selected on the basis of their potential clinical significance (possible mechanism in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):


Note: Combinations containing any of the following, depending on the amount present, may also interact with this medication.

Anabolic steroids or
Androgens or
Estrogens{26}    (concurrent use with sodium phosphates may increase the risk of edema, due to the sodium content {01})


» Angiotensin-converting enzyme (ACE) inhibitors or{25}
» Anti-inflammatory drugs, nonsteroidal (NSAIDs) or{29}{31}
» Cyclosporine or{29}{31}
» Diuretics, potassium-sparing or{07}
» Heparin, chronic use of or{29}{30}{31}
» Low-salt milk or
» Potassium-containing medications, other{07}{25} or
» Salt substitutes{29}    (concurrent use with potassium phosphate may result in hyperkalemia, especially in patients with renal impairment; patient should have serum potassium concentration determinations at periodic intervals)


» Antacids, aluminum- or magnesium-containing or{07}{08}{11}{13}
Oxalates, found in large quantities in rhubarb and spinach or
Phytates, in bran and whole-grain cereals    (concurrent use with phosphates may bind the phosphate and prevent its absorption)


» Calcium-containing medications, including dietary supplements and antacids    (concurrent use with phosphates may increase risk of deposition of calcium in soft tissues, if serum ionized calcium is high; also, phosphate absorption may be reduced because of formation of large amounts of insoluble phosphate {01} {28})


» Corticosteroids, glucocorticoid, especially with significant mineralocorticoid activity or
» Corticosteroids, mineralocorticoid or
» Corticotropin (ACTH)    (concurrent use with sodium phosphates may result in edema, due to the sodium content {01} {08} {20})


» Digitalis glycosides{02}    (use of potassium phosphates injection in digitalized patients with severe or complete heart block is not recommended because of possible hyperkalemia)


Iron supplements    (concurrent use with foods or medicines containing phosphates will decrease iron absorption because of the formation of less soluble or insoluble complexes; iron supplements should not be taken within 1 hour before or 2 hours after ingestion of phosphates {33})


» Phosphate-containing medication, other    (concurrent use with other phosphate containing medications may increase the risk of hyperphosphatemia, especially in patients with renal disease {34})


Salicylates    (concurrent use with potassium and sodium phosphates combination or monobasic potassium phosphate may increase plasma concentrations of salicylates since salicylate excretion is decreased in acidified urine; addition of these phosphates to patients stabilized on a salicylate may lead to toxic salicylate concentrations {06})


» Sodium-containing medications    (concurrent use with sodium phosphates may increase the risk of edema, especially in patients with renal disease {01})


Vitamin D, including calcifediol and calcitriol    (concurrent use with phosphorus-containing medications in high doses may increase the potential for hyperphosphatemia because of vitamin D enhancement of phosphate absorption {11} {28})


Zinc supplements    (concurrent use of phosphorus-containing medications with zinc supplements may reduce zinc absorption by formation of nonabsorbable complexes; phosphorus-containing medications should be taken 2 hours after zinc supplements {34} {35} {36})



Laboratory value alterations
The following have been selected on the basis of their potential clinical significance (possible effect in parentheses where appropriate)—not necessarily inclusive (» = major clinical significance):

With diagnostic tests results
Skeletal imaging    (saturation of bone binding sites by phosphorus ions in phosphates may cause decreased bone uptake of technetium Tc 99m–labeled diagnostic aids during bone imaging {15})


Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Except under special circumstances, this medication should not be used when the following medical problems exist:
» Hyperphosphatemia{01}{06}    (phosphates may further increase serum phosphate concentrations, especially in patients with renal disease {34})


» Renal function impairment, severe—less than 30% of normal{06}    (use may result in increased serum phosphate concentrations)


Urinary tract infections caused by urea splitting organisms    (use of phosphates may predispose to struvite stone formation {44})


» Urolithiasis, magnesium ammonium phosphate, infected{06}    (condition may be exacerbated)


Risk-benefit should be considered when the following medical problems exist

For all phosphates:
» Conditions in which high phosphate concentrations may be encountered, such as:{01}
Hypoparathyroidism
Renal disease, chronic
Rhabdomyolysis{38}{39}    (administration of phosphates may further increase serum phosphate concentrations)


» Conditions in which low calcium concentrations may be encountered, such as:{01}
Hypoparathyroidism{06}
Osteomalacia{08}
Pancreatitis, acute{06}
Renal disease, chronic
Rhabdomyolysis{38}{40}
Rickets{08}    (administration of phosphates may further decrease serum calcium concentrations)


Sensitivity to potassium, sodium, or phosphates
For potassium-containing phosphates only:
Cardiac disease, particularly in digitalized patients{01}    (condition may be exacerbated)


» Conditions in which high potassium concentrations may be encountered, such as:{02}
Adrenal insufficiency, severe—Addison's disease{06}
Dehydration, acute{06}
Pancreatitis{38}
Physicial exercise, strenuous, in unconditioned persons{32}
Renal insufficiency, severe{06}
Rhabdomyolysis{38}{39}
Tissue breakdown, extensive, such as severe burns{06}    (increased serum potassium concentrations leading to cardiac arrest may occur; exercise-induced hyperkalemia is transient and is a problem only in patients with renal insufficiency or those taking medications that increase serum potassium {32})


Myotonia congenita{06}    (condition may be exacerbated)


For sodium-containing phosphates only:
Cardiac failure or{01}
Cirrhosis of liver or severe hepatic disease or{01}
Edema, peripheral and pulmonary or{01}
» Hypernatremia or{01}
Hypertension or{01}
Renal function impairment or{01}
Toxemia of pregnancy{01}    (sodium salts should be used cautiously in patients with these conditions to prevent exacerbation; also, patients on sodium restricted diets should not use sodium phosphates)



Patient monitoring
The following may be especially important in patient monitoring (other tests may be warranted in some patients, depending on condition; » = major clinical significance):


For all phosphates
Calcium concentrations, serum and{01}{06}
Phosphorus concentrations, serum and{01}{06}
Potassium concentrations, serum and{06}
Renal function and{01}{08}
Sodium concentrations, serum{01}    (determinations may be required at frequent intervals during therapy, especially during intravenous therapy; high serum phosphate concentrations increase the incidence of extraskeletal calcification)


For potassium phosphates injection only
Electrocardiogram (ECG)    (may be required at frequent intervals during intravenous therapy)




Side/Adverse Effects
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Incidence less frequent or rare
    
Fluid retention (swelling of feet or lower legs; weight gain)
    
hyperkalemia (confusion; tiredness or weakness; irregular or slow heartbeat; numbness or tingling around lips, hands, or feet; unexplained anxiety; weakness or heaviness of legs; shortness of breath or troubled breathing){02}{17}
    
hypernatremia (confusion; tiredness or weakness; convulsions; decrease in amount of urine or in frequency of urination; fast heartbeat; headache or dizziness; increased thirst)
    
hyperphosphatemia or{02}{17} hypocalcemic tetany{01}{17}{38}{41} (convulsions, muscle cramps, numbness, tingling, pain, or weakness in hands or feet; shortness of breath, tremor or troubled breathing)
    
metastatic calcification {45}{46}



Those indicating need for medical attention only if they continue or are bothersome
Incidence less frequent
—for oral dosage forms only    
Laxative effect or diarrhea {03}{04}{05}{06}
    
nausea or vomiting {06}
    
stomach pain{06}





Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Phosphates (Systemic).

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):


Importance of diet
Importance of proper nutrition; supplement under physician's care may be needed because of inadequate dietary intake or increased requirements

Food sources of phosphorus

Recommended daily intake for phosphorus

Before using this medication
»   Conditions affecting use, especially:
Sensitivity to potassium, sodium, or phosphates
Other medications, especially angiotensin-converting (ACE) inhibitors, antacids, calcium-containing medications, corticosteroids, corticotropin (ACTH), cyclosporine, digitalis glycosides, chronic use of heparin, low-salt milk, nonsteroidal anti-inflammatory drugs, potassium-containing medications, potassium-sparing diuretics, salt substitutes, or sodium-containing medicines
Other medical problems, especially acute dehydration, acute pancreatitis, Addison's disease, edema, hypernatremia, hyperphosphatemia, hypoparathyroidism, infected urolithiasis, osteomalacia, rickets, severe dehydration, severe kidney disease

Proper use of this medication
Taking dissolved in water

» Taking after meals or with food to minimize possible stomach upset or laxative action

» Importance of high fluid intake (8-ounce glass of water every hour) to prevent kidney stones

» Importance of not taking more medication than the amount recommended

» For patients taking sodium-containing phosphates: Importance of low-sodium diet

» Proper dosing
Missed dose: Taking as soon as possible; not taking if within 1 or 2 hours of next dose; not doubling doses

» Proper storage

Precautions while using this medication
Regular visits to physician to check progress during therapy

Not taking iron supplements within 1 to 2 hours of phosphates

Checking with physician before beginning exercise program if on potassium-containing phosphate

Possible need for potassium or sodium restriction


Side/adverse effects
Signs of potential side effects, especially hyperkalemia, hypernatremia, hyperphosphatemia, hypocalcemic tetany, or fluid retention


General Dosing Information
The normal concentration of serum inorganic phosphate is 3 to 4.5 mg (0.1 to 0.15 mmol) per 100 mL in adults and 4 to 7 mg (0.13 to 0.2 mmol) per 100 mL in children. {01}

For oral dosage forms
Before this medication is taken, it must be thoroughly dissolved in water.

For parenteral dosage forms
Before administration, the concentrated phosphates injection (3 mmol of phosphorus per mL) must be diluted and thoroughly mixed with a larger volume of fluid. {01} {02}

The dose and rate of administration must be individualized. {02}

When used as an electrolyte replenisher, a dose of the equivalent of 10 to 15 mmol (310 mg to 465 mg) of phosphorus a day is usually sufficient to maintain normal serum phosphate, although larger amounts may be required in hypermetabolic states. {01}

The solution should be infused slowly to avoid phosphate intoxication.

Intravenous infusion of phosphates in high concentrations may cause hypocalcemia {01}.

Diet/Nutrition
This medication should be taken immediately after a meal or with food to minimize possible stomach upset or laxative action. {03}

Recommended dietary intakes for phosphorus are defined differently worldwide.


For U.S.:
The Recommended Dietary Allowances (RDAs) for vitamins and minerals are determined by the Food and Nutrition Board of the National Research Council and are intended to provide adequate nutrition in most healthy persons under usual environmental stresses. In addition, a different designation may be used by the FDA for food and dietary supplement labeling purposes, as with Daily Value (DV). DVs replace the previous labeling terminology United States Recommended Daily Allowances (USRDAs). {11} {47}



For Canada:
Recommended Nutrient Intakes (RNIs) for vitamins, minerals, and protein are determined by Health and Welfare Canada and provide recommended amounts of a specific nutrient while minimizing the risk of chronic diseases. {49}

Daily recommended intakes for phosphorus are generally defined as follows: {16} {48}

Persons
U.S.
(mg)
Canada
(mg)
Infants and children
Birth to 3 years of age
300–800
150–350
4 to 6 years of age
800
400
7 to 10 years of age
800
500–800
Adolescent and adult males
800–1200
700–1000
Adolescent and adult females
800–1200
800–850
Pregnant females
1200
1050
Breast-feeding females
1200
1050


The best dietary sources of phosphorus include dairy products {38}, meat, poultry, fish, and cereal products. {11}


For treatment of adverse effects
Recommended treatment consists of the following:

   • Withholding administration of phosphates.
   • Correcting deficient serum electrolyte concentrations (such as that of calcium).

POTASSIUM PHOSPHATES


Oral Dosage Forms

MONOBASIC POTASSIUM PHOSPHATE TABLETS FOR ORAL SOLUTION

Usual adult and adolescent dose
Acidifier (urinary) or
Antiurolithic or
Electrolyte replenisher
Oral, 1 gram (228 mg or 7.4 mmol of phosphorus) in 180 to 240 mL of water four times a day, with meals and at bedtime. {07}


Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, the equivalent of 200 mg (6.4 mmol) of phosphorus in 60 mL of water four times a day, after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose.


Strength(s) usually available
U.S.—


500 mg (114 mg [3.7 mmol] of phosphorus) (Rx) [K-Phos Original (scored)]

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Preparation of dosage form:
Soak the tablets in 60 or 75 mL of water for 2 to 5 minutes. Stir well to dissolve completely before swallowing. {07}

Auxiliary labeling:
   • Do not swallow tablet.
   • Dissolve tablet in a full glass (8 ounces) of water.

Additional information:
Each 500-mg tablet supplies 114 mg (3.7 mmol) of phosphorus and 3.7 mEq (144 mg) of potassium. {07}


POTASSIUM PHOSPHATES CAPSULES FOR ORAL SOLUTION

Usual adult and adolescent dose
Electrolyte replenisher
Oral, 1.45 grams (250 mg or 8 mmol of phosphorus) in 75 mL of water or juice four times a day, after meals and at bedtime. {06}


Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, the equivalent of 200 mg (6.4 mmol) of phosphorus in 60 mL of water or juice four times a day, after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose. {06}


Strength(s) usually available
U.S.—


1.45 grams (250 mg [8 mmol] of phosphorus) (OTC) [Neutra-Phos-K]

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Preparation of dosage form:
Empty contents of capsule into 60 or 75 mL of water or juice and stir well. {06}

Auxiliary labeling:
   • Do not swallow filled capsule.
   • Mix contents of each capsule with one-third glass of water or juice. {06}

Additional information:
Each 1.45-gram capsule supplies 250 mg (8 mmol) of phosphorus and 14.25 mEq (556 mg) of potassium, as monobasic and dibasic potassium phosphates per 75 mL of water or juice {06}, or 200 mg (6.4 mmol) per 60 mL of water or juice, when reconstituted according to manufacturer's instructions.


POTASSIUM PHOSPHATES FOR ORAL SOLUTION

Usual adult and adolescent dose
Electrolyte replenisher
Oral, the equivalent of 250 mg (8 mmol) of phosphorus four times a day, after meals and at bedtime. {03}


Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, the equivalent of 200 mg (6.4 mmol) of phosphorus four times a day, after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose. {03}


Size(s) usually available:
U.S.—


1.45 grams (250 mg [8mmol] of phosphorus) (OTC) [Neutra-Phos-K]


71 grams (250 mg [8 mmol] of phosphorus) (OTC) [Neutra-Phos-K]

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Preparation of dosage form:
To prepare solution, add the contents of one bottle (71 grams) of powder concentrate, supplied by the manufacturer, to a sufficient amount of water to make 1 gallon (3.785 liters) of solution or the contents of one packet of powder concentrate to a sufficient amount of water to make 1/3 of a glass (approximately 2.5 ounces) of water. Shake the container for 2 or 3 minutes or until all the powder is dissolved. Solution should not be diluted. {03}

Stability:
Solution can be stored for 60 days. {03}

Additional information:
Each 75 mL of solution or the solution prepared from one packet, when constituted according to manufacturer's instructions, supplies 250 mg (8 mmol) of phosphorus and 14.25 mEq (556 mg) of potassium, as monobasic and dibasic potassium phosphates. {03}



Parenteral Dosage Forms

POTASSIUM PHOSPHATES INJECTION USP

Note: Potassium phosphates injection must be diluted prior to intravenous administration {02}.


Usual adult and adolescent dose
Electrolyte replenisher
Intravenous infusion, the equivalent of 10 mmol (310 mg) of phosphorus a day.


Usual pediatric dose
Electrolyte replenisher
Intravenous infusion, the equivalent of 1.5 to 2 mmol (46.5 to 62 mg) of phosphorus a day.


Strength(s) usually available
U.S.—


224 mg of monobasic potassium phosphate and 236 mg of dibasic potassium phosphate (3 mmol [93 mg] of phosphorus) per mL (Rx)[Generic]

Canada—


224 mg of monobasic potassium phosphate and 236 mg of dibasic potassium phosphate (3 mmol [93 mg] of phosphorus) per mL (Rx)[Generic]

Packaging and storage:
Store between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer.

Incompatibilities:
Precipitate may form when phosphates are added to solution containing calcium or magnesium. {18}

Additional information:
Each mL of potassium phosphates injection supplies 283.5 mg of phosphate (approximately 3 mmol [93 mg] of phosphorus) and 4.4 mEq (170.2 mg) of potassium. {01}


POTASSIUM AND SODIUM PHOSPHATES


Oral Dosage Forms

MONOBASIC POTASSIUM AND SODIUM PHOSPHATES TABLETS FOR ORAL SOLUTION

Usual adult and adolescent dose
Acidifier (urinary) or
Antiurolithic or
Electrolyte replenisher
Oral, 250 mg (8 mmol) of phosphorus with a full glass (240 mL) of water four times a day, after meals and at bedtime. {08}

Note: When the urine is difficult to acidify, a dose of the equivalent of 250 mg (8 mmol) of phosphorus may be administered every two hours, not to exceed 2 grams of phosphorus in a twenty-four–hour period.



Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, 200 mg (6.4 mmol) of phosphorus in 60 mL of water four times a day, after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose.


Strength(s) usually available
U.S.—


155 mg of monobasic potassium phosphate and 350 mg of anhydrous monobasic sodium phosphate (125.6 mg [4 mmol] of phosphorus) (Rx) [K-Phos M. F (scored)]


155 mg of monobasic potassium phosphate, 130 mg of hydrous monobasic sodium phosphate, and 852 mg of anhydrous dibasic sodium phosphate (250 mg [8 mmol] of phosphorus) (Rx) [K-Phos Neutral{10}]


305 mg of monobasic potassium phosphate and 700 mg of anhydrous monobasic sodium phosphate (250 mg [8 mmol] of phosphorus) (Rx) [K-Phos No. 2{08}]

Canada—
Not commercially available.

Packaging and storage:
Store between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Auxiliary labeling:
   • Do not swallow tablet.
   • Dissolve tablet in a full glass (8 ounces) of water.

Additional information:
A dose of 155 mg of monobasic potassium phosphate and 350 mg of anhydrous monobasic sodium phosphate supplies 125.6 mg (4 mmol) of phosphorus, 1.14 mEq (44.5 mg) of potassium, and 2.9 mEq (67 mg) of sodium. {08}

A dose of 305 mg of monobasic potassium phosphate and 700 mg of anhydrous monobasic sodium phosphate supplies 250 mg (8 mmol) of phosphorus, 2.3 mEq (88 mg) of potassium, and 5.8 mEq (134 mg) of sodium.

A dose of 155 mg of monobasic potassium phosphate, 130 mg of hydrous monobasic sodium phosphate, and 852 mg of anhydrous dibasic sodium phosphate supplies 250 mg (8 mmol) of phosphorus, 1.15 mEq (45 mg) of potassium, and 12.9 mEq (298 mg) of sodium. {10}


POTASSIUM AND SODIUM PHOSPHATES CAPSULES FOR ORAL SOLUTION

Usual adult and adolescent dose
Electrolyte replenisher
Oral, 1.25 grams (250 mg or 8 mmol of phosphorus) in 75 mL of water or juice four times a day, after meals and at bedtime. {05}


Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, the equivalent of 200 mg (6.4 mmol) of phosphorus in 60 mL of water or juice four times a day, after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose. {05}


Strength(s) usually available
U.S.—


1.25 grams (250 mg [8 mmol] of phosphorus) (OTC) [Neutra-Phos]

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Preparation of dosage form:
Empty contents of capsule into 75 mL of water or juice and stir well. {05}

Auxiliary labeling:
   • Do not swallow filled capsule.
   • Mix contents of each capsule with one-third glass of water or juice. {05}

Additional information:
Each 1.25-gram capsule supplies 250 mg (8 mmol) of phosphorus, 278 mg (7.125 mEq) of potassium, and 164 mg (7.125 mEq) of sodium. {05}


POTASSIUM AND SODIUM PHOSPHATES FOR ORAL SOLUTION

Usual adult and adolescent dose
Electrolyte replenisher
Oral, 250 mg (8 mmol) of phosphorus four times a day, after meals and at bedtime. {04}


Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, 200 mg (6.4 mmol) four times a day after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose. {04}


Size(s) usually available:
64 grams (250 mg or 8 mmol of phosphorus per 75 mL, when reconstituted according to manufacturer's instruction).
U.S.—


1.25 grams (250 mg [8mmol] of phosphorus) (OTC) [NeutraPhos]


64 grams (250 mg [8 mmol] of phosphorus) (OTC) [Neutra-Phos]

Canada—
Not commercially available.

Packaging and storage:
Store between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Preparation of dosage form:
To prepare solution, add the contents of one bottle (64 grams) of dibasic potassium and sodium phosphates and monobasic potassium sodium phosphates powder concentrate, supplied by the manufacturer, to a sufficient amount of water to make 1 gallon (3.785 liters) of solution or the contents of one packet, supplied by the manufacturer, to a sufficient amount of water to make 1/3 glass of water (approximately 2.5 ounces) of solution. Shake for 2 or 3 minutes or until all the powder is dissolved. Solution should not be diluted. {04}

Stability:
Solution can be stored for 60 days. {04}

Additional information:
Each 75 mL of solution or solution prepared from one packet supplies 250 mg (8 mmol) of phosphorus, 7.125 mEq (278 mg) of potassium, and 7.125 mEq (164 mg) of sodium.


POTASSIUM AND SODIUM PHOSPHATES TABLETS FOR ORAL SOLUTION

Usual adult and adolescent dose
Electrolyte replenisher
Oral, the equivalent of 250 mg (8 mmol) of phosphorus with a full glass (240 mL) of water four times a day.


Usual pediatric dose
Electrolyte replenisher
Children up to 4 years of age: Oral, 200 mg (6.4 mmol) of phosphorus in 60 mL of water four times a day, after meals and at bedtime.
Children 4 years of age and over: See Usual adult and adolescent dose.


Strength(s) usually available
U.S.—


250 mg (8 mmol) of phosphorus (Rx) [Uro-KP-Neutral]

Canada—


250 mg (8 mmol) of phosphorus (Rx) [Uro-KP-Neutral]

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), in a well-closed container, unless otherwise specified by manufacturer.

Auxiliary labeling:
   • Do not swallow tablet.
   • Dissolve tablet in a full glass (8 ounces) of water.

Additional information:
Each tablet supplies 250 mg (8 mmol) of phosphorus, 1.28 mEq (50 mg) of potassium, and 10.8 mEq (250 mg) of sodium, as anhydrous dibasic sodium phosphate, anhydrous dibasic potassium phosphate, and anhydrous monobasic sodium phosphate. {09}


SODIUM PHOSPHATES


Parenteral Dosage Forms

Note: Sodium phosphates injection must be diluted prior to intravenous administration. {01}


SODIUM PHOSPHATES INJECTION USP

Usual adult and adolescent dose
Electrolyte replenisher
Intravenous infusion, 10 to 15 mmol (310 to 465 mg) of phosphorus a day. {01}


Usual pediatric dose
Electrolyte replenisher
Intravenous infusion, 1.5 to 2 mmol of phosphorus per kg of body weight a day. {01}


Strength(s) usually available
U.S.—


276 mg of hydrous monobasic sodium phosphate and 142 mg of anhydrous dibasic sodium phosphate (3 mmol [93 mg] of phosphorus) per mL (Rx)[Generic]{01}

Canada—
Not commercially available.

Packaging and storage:
Store below 40 °C (104 °F), preferably between 15 and 30 °C (59 and 86 °F), unless otherwise specified by manufacturer. Protect from freezing.

Incompatibilities:
Precipitate may form when sodium phosphates injection is added to solution containing calcium or magnesium. {18}

Additional information:
Each mL of sodium phosphates injection supplies 285 mg of phosphate (approximately 3 mmol [93 mg] of phosphorus) and 4 mEq (92 mg) of sodium. {01}



Revised: 08/18/2000



References
  1. Sodium Phosphates Injection pi, Lypho Med, rev 1/87, U.S.
  1. Potassium Phosphates Injection pi, Lypho Med, rev 1/87, U.S.
  1. Neutra-Phos-K label information, Willen Drug Co. rev 1/89, U.S.
  1. Neutra-Phos powder label information, Willen Drug Co, rev 1/89, U.S.
  1. Neutra-Phos powder conc capsules label information, Willen Drug Co, rec 1/89, U.S.
  1. Neutra-Phos-K powder concentrate capsules, Willen Drug Co, rev 1/89, U.S.
  1. K-Phos original pi, 1990 PDR, p 652.
  1. K-Phos M.F./K-Phos No. 2 pi, 1990 PDR, p 652.
  1. Uro-KP-Neutral pi, 1990 PDR, p 2163.
  1. K-Phos Neutral pi, 1990 PDR, p 652.
  1. National Research Council. Recommended Dietary Allowances, 10th Edition.
  1. Hall, R et al. Hypophosphatemia in breast-fed low-birth-weight infants following initial hospital discharge. Am J Dis Child 1989, 143[10]: 1191–5.
  1. Tolstoi L. Hypophosphatemia. U.S. Pharmacist April 1987, pp H-7–H-13.
  1. Berner Y and Shike M. Consequences of phosphate imbalance. Annual Review of Nutrition 1988, 8: 121–148.
  1. Hladik W, et al. Essentials of Nuclear Medicine Science. 1987, p 193.
  1. Shank W. Phosphorus preparations for the management of hypophosphatemia. Hosp Pharm 1985, 20: 459–463.
  1. Lentz R, et al. Treatment of severe hypophosphatemia. Annals of Int Med 1978, 89: 941–944.
  1. Trissel L. Handbook on Injectable Drugs, 5th Edition.
  1. Stoff J. Phosphate homeostasis and hypophosphatemia. 1982, Am J of Med 72: 489–495.
  1. Juan D and Elrazak M. Hypophosphatemia in hospitalized patients. JAMA 1979, 24[2]: 163–164.
  1. Panel comment, 1988 revision cycle.
  1. Pak C. Medical management of nephroliathiasis. J Urology 1982, 128: 1157–1164.
  1. Insogna K, Ellison A, Burtis W, Sartori L, Lang R, Broadus A. Trichlorthiazide and oral phosphate therapy in patients with absorptive hypercalcuria. 1989 141: 269–274.
  1. Panel comments, 1991 revision cycle.
  1. Drug Information Facts, 1990.
  1. Panelist comment, 1991 revision cycle.
  1. Pak C, Holt K, Zerwekk J, Barilla D. Effects of orthophosphate therapy on the crystallization of calcium salts in urine. Mineral Electrolyte Metab 1978, 1: 147–154.
  1. Goodman and Gilman, The Pharmacological Basis of Therapeutics, 8th Edition, 1990.
  1. Panelist comment, 1991 revision cycle.
  1. Aull L, et al. Heparin-induced hyperkalemia. DICP 1990, 24: 244–246.
  1. Saxena K. Clinical features and management of poisoning due to potassium chloride. Med Toxicol Adverse Drug Exp 1989, 4[6]: 429–443.
  1. Hazeyama Y and Sparks H. A model of potassium in efflux during exercise of skeletal muscle. Am Physiol Soc 1979, pp R83–R90.
  1. Roe D. Diet and Drug Interactions, AVI Press, l989.
  1. Panelist comment, 1991 revision cycle.
  1. Greger J and Snedeker S. Effect of dietary protein and phosphorus levels on the utilization of zinc, copper and manganese by adult males. J Nutr 1980, 110: 2243–2253.
  1. Pecoud A, Donzel P, Schelling J. Effect of foodstuffs on the absorption of zinc sulfate. Clin Pharm Ther 1974, 17[4]: 469–474.
  1. Panelists comment, 1991 revision.
  1. Panelist comment, 1991 revision cycle.
  1. Ward M. Factors predictive of acute renal failure in rhabdomyolysis. Arch Int Med 1988, 148: 1553–1557.
  1. Garcia de Vinuesa S, Ahijado F, Luno J. Serum calcium and parathyroid hormone derangement in rhabdomyolysis. Nephron 1989, 52: 107–108.
  1. The Merck Manuel, Vol 1, 14th Edition.
  1. Edmondson S, Almquist T. Iatrogenic hypocalcemic tetany. Annals of Emerg Med 1990, 19: 938–940.
  1. McCabe M, Sibert J, Routledge P. Phosphate enemas in childhood: cause for concern. Br Med J 1991, 302: 1074–1075.
  1. Panel comments, 1991 revision cycle.
  1. Panelist comment, 1991 revision cycle.
  1. Besunder J, Smith P. Toxic effects of electrolyte and trace mineral administration in the intensive care unit. Crit Care Clin 1991, 7[3]: 659–693.
  1. Food and Drug Administration. Focus on food labeling. FDA Consumer. May, 1993.
  1. Fleeger CA, editor. USP dictionary of USAN and international drug names, 1995. Rockville, MD: The United States Pharmacopeial Convention, Inc., 1994: 548.
  1. Health and Welfare Canada. Nutrition recommendations, the report of the scientific committee. Ottawa: Canadian Government Publishing Centre, 1990: 11-2.
  1. Nutrition and Electrolytes panel meeting, 1995.
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