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Phospha 250 Neutral

Generic K-Phos Neutral
Used for Hypophosphatemia, Kidney Stones

Potassium phosphate/sodium phosphate is a phosphorus supplement. Some brands (e.g., K-PHOS® No. 2) are used as urinary acidifiers to help prevent kidney stones. Other brands (e.g., K-PHOS Neutral, Phospha 250 Neutral) are used to raise phosphate and pyrophosphate levels in the urine. This supplement comes as oral tablets and is typically taken by mouth 4 times a day. But specific dosing can also depend on the brand and your body's response to the medication. Diarrhea, nausea, and stomach pain are possible side effects.

Reviewed by:
reviewerSarah Lobello Pearson, PharmD
reviewerCydnee Ng, PharmD
Last reviewed on April 10, 2022
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What is Potassium phosphate/sodium phosphate?

What is Potassium phosphate/sodium phosphate used for?

How Potassium phosphate/sodium phosphate works

Potassium phosphate/sodium phosphate is a phosphorus supplement.

Some brands are taken to acidify the urine, meaning to lower the urinary pH. This can help prevent kidney stones, ease odor and skin rash caused by urine that has too much ammonia, and help methenamine hippurate (Hiprex) work better at controlling urinary tract infections (UTIs).

Other brands are taken as a phosphorus supplement. Phosphorus is a mineral that has many important roles in the body, such as formation of bone cells and making energy. Potassium phosphate/sodium phosphate can also be taken to raise phosphate and pyrophosphate levels in the urine.

Drug facts

Common BrandsK-Phos No. 2, K-Phos Neutral
Drug ClassUrinary acidifier
Controlled Substance ClassificationNot a controlled medication
Generic StatusLower-cost generic available
AvailabilityPrescription or over-the-counter
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Side effects of Potassium phosphate/sodium phosphate

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

  • Diarrhea
  • Nausea
  • Stomach pain
  • Vomiting
  • Bone and joint pain

Less Common Side Effects

  • Headache
  • Dizziness
  • Confusion
  • Numbness, tingling, pain, or weakness of hands or feet
  • Muscle cramps

Potassium phosphate/sodium phosphate serious side effects

Contact your healthcare provider immediately if you experience any of the following.

Seizures

Source: DailyMed

The following Potassium phosphate/sodium phosphate side effects have also been reported

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Incidence not known

Bone pain

convulsions

decreased urine output

dizziness

fast or irregular heartbeat

headache

joint pain

mental confusion

muscle cramps

numbness or tingling around the lips

numbness, tingling, pain, or weakness of the hands or feet

shortness of breath

swelling of the feet or lower legs

troubled breathing

unusual thirst

unusual tiredness or weakness

unusual weight gain

weakness or heaviness of the legs

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Incidence not known

Diarrhea

nausea

stomach pain

vomiting

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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Pros and cons of Potassium phosphate/sodium phosphate

Pros

  • Can help lower risk of kidney stones
  • Can help some UTI antibiotics work better
  • Taken by mouth

Cons

  • Typically has to be taken 4 times a day
  • Can cause diarrhea and stomach upset
  • Can't be used in people with severe kidney problems
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Pharmacist tips for Potassium phosphate/sodium phosphate

pharmacist
  • Take each dose of potassium phosphate/sodium phosphate with a full glass of water.
  • Potassium phosphate/sodium phosphate can cause mild diarrhea during the first few days of taking it. It's important to stay hydrated during this time so your body doesn't lose too much fluids. If the diarrhea is severe or doesn't go away after a few days, tell your care team.
  • Since potassium phosphate/sodium phosphate can affect your electrolyte levels, your prescriber might want to do blood tests to check your calcium, phosphorus, sodium, and potassium levels while taking the medication.
  • Don't take potassium phosphate/sodium phosphate with antacids that contain magnesium, aluminum, or calcium. Doing so can prevent your body from absorbing phosphate.
  • If you take other potassium-containing medications or potassium-sparing diuretics with potassium phosphate/sodium phosphate, you're at higher risk for having high potassium levels. Talk to your healthcare professional (HCP) if you have nausea, irregular heartbeat, or muscle weakness while taking potassium phosphate/sodium phosphate.
  • Tell your healthcare team about all the medications you're taking. Taking certain medications, including hydralazine and corticosteroids can cause your sodium levels to rise too high. This can put you at risk for seizures and confusion.
  • If you have kidney stones, you could pass them when starting potassium phosphate/sodium phosphate. Tell your prescriber if your kidney stone symptoms get worse.
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Risks and warnings for Potassium phosphate/sodium phosphate

Potassium phosphate/sodium phosphate can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Passing of old kidney stones

  • Risk factors: History of kidney stones

Starting treatment with potassium phosphate/sodium phosphate might cause you to pass old kidney stones through your urine. Small kidney stones will pass more easily, causing little to no pain. Call your prescriber if you think you're passing old kidney stones, or if you experience severe pain, fever, or blood in the urine.

Worsening of certain health conditions

Potassium phosphate/sodium phosphate might not be safe to take if you have certain health conditions. Talk to your healthcare professional before taking this medication if you have heart conditions or high blood pressure. This medication might not be appropriate for people with liver problems or pancreatitis as well. Make sure to let your care team know your full medical history so they can decide if potassium phosphate/sodium phosphate is safe for you.

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Potassium phosphate/sodium phosphate dosage

The average cost for 120 tablets of 250mg of Potassium phosphate/sodium phosphate is $22.84 with a free GoodRx coupon. This is 54.97% off the average retail price of $50.72.
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DosageQuantityPrice as low asPrice per unit
250mg120 tablets$22.84$0.19

Typical dosage for Potassium phosphate/sodium phosphate

Different brands of potassium phosphate/sodium phosphate might contain different amounts of phosphate.

Some examples include:

K-Phos No. 2:

Each tablet contains 305 mg of potassium phosphate and 700 mg of sodium phosphate.

  • The typical dose is 1 tablet taken by mouth four times daily with a full glass of water. Your prescriber might raise the dose to 1 tablet every 2 hours if your urine isn't acidic enough. Don't take more than 8 tablets in a 24-hour period.

K-Phos Neutral and Phospha 250 Neutral:

Each tablet contains 852 mg of dibasic sodium phosphate, 155 mg of monobasic potassium phosphate, and 130 mg of monobasic sodium phosphate.

  • Adults: The typical dose is 1 to 2 tablets by mouth four times daily (with meals and at bedtime with a full glass of water).
  • Children over 4 years old: The typical dose is 1 tablet by mouth four times daily (with meals and at bedtime with a full glass of water).
  • Children ages 4 years and younger: Ask your child's pediatrician.
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Interactions between Potassium phosphate/sodium phosphate and other drugs

Potassium phosphate/sodium phosphate may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking. The list below does not include all possible drug interactions with Potassium phosphate/sodium phosphate. Please note that only the generic name of each medication is listed below.

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this dietary supplement, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this dietary supplement with any of the following medicines is not recommended. Your doctor may decide not to treat you with this dietary supplement or change some of the other medicines you take.

Using this dietary supplement with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Using this dietary supplement with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Aluminum Carbonate, Basic
  • Aluminum Hydroxide
  • Aluminum Phosphate
  • Calcium Acetate
  • Calcium Carbonate
  • Calcium Citrate
  • Dihydroxyaluminum Aminoacetate
  • Dihydroxyaluminum Sodium Carbonate
  • Magaldrate
  • Magnesium Carbonate
  • Magnesium Hydroxide
  • Magnesium Oxide
  • Magnesium Trisilicate
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How much does Potassium phosphate/sodium phosphate cost?

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K-Phos Neutral (brand)
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$22.31

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Potassium phosphate/sodium phosphate (generic)
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$22.31

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Potassium phosphate/sodium phosphate contraindications

Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Potassium phosphate/sodium phosphate will not be safe for you to take.

  • Infected phosphate stones
  • Severe kidney damage
  • High blood phosphate levels
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What are alternatives to Potassium phosphate/sodium phosphate?

There are a number of medications that your doctor can prescribe in place of Potassium phosphate/sodium phosphate. Compare a few possible alternatives below.
Potassium phosphate/sodium phosphate
Used for:
$22.31Lowest GoodRx priceView prices
Used for:
  • Lowering urinary pH
$39.72Lowest GoodRx priceView prices

References

Best studies we found

Beach Products, Inc. (2023). K PHOS NEUTRAL- sodium phosphate, dibasic, anhydrous, potassium phosphate, monobasic, and sodium phosphate, monobasic, monohydrate tablet, coated [package insert]. DailyMed.

Beach Products, Inc. (2023). K-PHOS NO. 2- potassium phosphate, monobasic and sodium phosphate, monobasic, anhydrous tablet, coated [package insert]. DailyMed.

MedlinePlus. (2022). Phosphate in urine.

GoodRx Health has strict sourcing policies and relies on primary sources such as medical organizations, governmental agencies, academic institutions, and peer-reviewed scientific journals. Learn more about how we ensure our content is accurate, thorough, and unbiased by reading our editorial guidelines.