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potassium phosphate

Generic Name: potassium phosphate (poe TASS ee um FOSS fate)
Brand Name: Neutra-Phos-K

What is potassium phosphate?

Phosphorus is a naturally occurring substance that is important in every cell of the body. Phosphorous is contained in all body cells and is used for growth and repair of cells and tissues.

Potassium phosphate is used to treat or prevent hypophosphatemia (low blood levels of phosphorus). Potassium phosphate is sometimes added to intravenous (IV) fluids given to people who cannot eat or drink anything.

Potassium phosphate and sodium phosphate may also be used for purposes not listed in this medication guide.

What is the most important information I should know about 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.

What should I discuss with my healthcare provider before taking potassium phosphate?

You should not use potassium phosphate if you have:

  • high levels of potassium in your blood (hyperkalemia);

  • low levels of calcium in your blood (hypocalcemia); or

  • high levels of phosphorus in your blood (hyperphosphatemia).

To make sure this medicine is safe for you, tell your doctor if you have:

  • heart disease;

  • kidney disease; or

  • Addison's disease (an adrenal gland disorder).

It is not known whether potassium phosphate will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether potassium phosphate passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Potassium phosphate and sodium phosphate should not be given to a child younger than 4 years old without a doctor's advice.

How is potassium phosphate given?

Potassium phosphate is injected into a vein through an IV. A healthcare provider will give you this injection.

Potassium phosphate must be mixed with a liquid (diluent) before using it. If you are using the injections at home, be sure you understand how to properly mix and store the medicine.

Potassium phosphate must be given slowly.

While using this medicine, you may need frequent blood or urine tests.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose?

Use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

What happens if I overdose?

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

What should I avoid while taking potassium phosphate?

Ask your doctor before using an antacid, and use only the type your doctor recommends. Some antacids can make it harder for your body to absorb potassium phosphate and sodium phosphate.

Avoid taking a vitamin or mineral supplement that contains calcium or vitamin D, unless your doctor tells you to.

Do not use potassium supplements or salt substitutes while you are taking potassium phosphate and sodium phosphate, unless your doctor has told you to.

Potassium phosphate side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Tell your caregivers right away if you have any signs of electrolyte imbalance, such as:

  • numbness or tingly feeling around your mouth;

  • fast or slow heart rate;

  • a light-headed feeling, like you might pass out;

  • muscle tightness or contraction, overactive reflexes;

  • weakness or loss of movement in any part of your body;

  • slow or unusual heart rate;

  • nausea, confusion, weakness; or

  • numbness or tingling in your arms or legs.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Potassium phosphate dosing information

Usual Adult Dose for Dietary Supplement:

1 powder packet (1.45 g) reconstituted in 75 mL water and administered orally 4 times daily. This will provide 250 mg of inorganic phosphorus in each dose.

Usual Adult Dose for Constipation:

1 to 2 powder packet(s) reconstituted in 75 mL water and administered orally 4 times daily as needed to relieve constipation.

Usual Adult Dose for Hypophosphatemia:

0.15 to 0.3 mmol/kg/dose as an intravenous solution to infuse over 12 hours; may repeat as needed to achieve desired serum levels.

Alternative 1:
Serum phosphorus < 2 mg/dL: 15 mmol potassium phosphate/dose as an intravenous solution to infuse over 2 hours.

Alternative 2:
Serum phosphorus 2.3 to 3 mg/dL: 0.16 mmol/kg IV over 4 to 6 hours.
Serum phosphorus 1.6 to 2.2 mg/dL: 0.32 mmol/kg IV over 4 to 6 hours.
Serum phosphorus 1.5 or less: 0.64 mmol/kg IV over 8 to 12 hours.

Usual Pediatric Dose for Constipation:

< 4 years: 1 powder packet reconstituted in 75 mL water and administered orally 4 times daily as needed to relieve constipation.

> 4 years: 1 to 2 powder packet(s) reconstituted in 75 mL water and administered orally 4 times daily as needed to relieve constipation.

Usual Pediatric Dose for Hypophosphatemia:

Serum phosphorus normal, but recent phosphate loss: 0.08 mmol/kg/dose as an intravenous solution to infuse over 6 hours.

Serum phosphorus 0.5 to 1 mg/dL: 0.16 to 0.24 mmol/kg/dose as an intravenous solution to infuse over 6 hours.

Serum phosphorus < 0.5 mg/dL: 0.36 mmol/kg/dose as an intravenous solution to infuse over 6 hours.

What other drugs will affect potassium phosphate?

Tell your doctor about all your current medicines and any you start or stop using, especially:

  • digoxin, digitalis; or

  • a diuretic or "water pill" (especially amiloride, eplerenone, spironolactone, or triamterene).

This list is not complete. Other drugs may interact with potassium phosphate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Where can I get more information?

  • Your pharmacist can provide more information about potassium phosphate and sodium phosphate.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 1.01.

Date modified: November 30, 2016
Last reviewed: May 12, 2016

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