Potassium Phosphate Tablets

What is this medication?

POTASSIUM PHOSPHATE (poe TASS ee um FOS fate) prevents kidney stones caused by too much calcium in the body. It works by making your urine more acidic, which prevents the build up of calcium. It may also be used to prevent and treat low phosphorus levels in your body. Phosphorus is a mineral that plays an important role in maintaining the health of your bones, muscles, digestive tract, and nervous system. This medication can also help antibiotics for UTIs work better.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): K-Phos, Phospho-Trin


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What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Addison's disease
  • Diabetes
  • Heart disease
  • High levels of potassium or phosphorus in the blood
  • Kidney disease
  • An unusual or allergic reaction to potassium, phosphorus, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with food. Follow the directions on the package or prescription label. Dissolve this medication in 6 to 8 ounces of water as directed. Allow tablets to soak in water for 2 to 5 minutes or more. If part of the tablet does not dissolve, it may be crushed and then the solution stirred vigorously. Shake or stir well before taking. Take your medication at regular intervals. Do not take your medication more often than directed. Do not stop taking except on your care team's advice.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.


What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

  • Certain diuretics such as spironolactone, triamterene
  • Eplerenone
  • Sevelamer
  • Sodium polystyrene sulfonate

This medication may also interact with the following:

  • Antacids containing aluminum, magnesium, or calcium
  • Aspirin and aspirin-like medications
  • Certain medications for blood pressure or heart disease like lisinopril, losartan, quinapril, valsartan
  • Medications that lower your chance of fighting infection such as cyclosporine, tacrolimus
  • NSAIDs, medications for pain and inflammation, like ibuprofen or naproxen
  • Other potassium or phosphorus supplements
  • Salt substitutes

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.


What should I watch for while using this medication?

Visit your care team for regular checkups. You may need lab work done regularly.

If you have kidney stones, you may pass old stones when starting this medication.

Side effects like stomach upset, nausea and diarrhea happen more when this medication is not mixed properly or taken without food. Follow mixing instructions exactly each time you take a dose.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • High phosphorus level—muscle pain or cramps, bone or joint pain, numbness and tingling around the mouth
  • High potassium level—muscle weakness, fast or irregular heartbeat

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Diarrhea
  • Headache
  • Nausea
  • Stomach pain
  • Vomiting

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light. Throw away any unused medication after the expiration date.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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