provider image
Welcome! You’re in GoodRx for healthcare professionals. Now, you’ll enjoy a streamlined experience created specifically for healthcare professionals.
Skip to main content

Phospha 250 Neutral

Generic K-Phos Neutral
Used for Hypophosphatemia, Kidney Stones
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:
reviewer
Sarah Lobello Pearson, PharmD
reviewer
Cydnee Ng, PharmD
Last reviewed on April 10, 2022
BasicsSide effectsPros & consPharmacist tipsFAQsWarningsDosageInteractionsCostContraindicationsAlternativesReferencesPricesMedicare
basics-icon

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.

Are you looking for information on K-Phos (potassium phosphate) dissolvable tablets instead?

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
coupon-save-icon

Get your GoodRx coupon

Avg retail price
$69.29(save 70.32%)
GoodRx discount
$20.56
See prices
basics-icon

What are the 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

Other Side Effects

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

Serious Side Effects

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

Source: DailyMed

The following 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.

pros-and-cons

Pros and cons of Potassium phosphate/sodium phosphate

thumbs-up

Pros

Can help lower risk of kidney stones

Can help some UTI antibiotics work better

Taken by mouth

thumbs-down

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

pharmacist-tips

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.

            • 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.

              faqs

              Frequently asked questions about Potassium phosphate/sodium phosphate

              How much phosphorus does a person need?
              The amount of phosphorus you need depends on your age and medical condition(s). In general, adults need 700 mg of phosphorus a day. Children and teens need different amounts. If you're taking K-PHOS Neutral as a phosphorus supplement, each tablet provides about 25% of the U.S. recommended daily allowance of phosphorus for adults. Talk to your healthcare professional (HCP) about how much phosphorus you should get every day.
              What are some side effects of potassium phosphate/sodium phosphate?
              Some potential side effects of potassium phosphate/sodium phosphate include diarrhea, nausea, vomiting, stomach pain, bone pain, and joint pain. It can also cause headaches, dizziness, and muscle cramps. These aren't all possible side effects from potassium phosphate/sodium phosphate. Review the full product information and discuss your risk of side effects with your HCP.
              Can potassium phosphate/sodium phosphate be crushed?
              Check with your prescriber or pharmacist if your specific brand of potassium phosphate/sodium phosphate can be split or crushed. Many tablets have a special coating that shouldn't be broken. But a particular brand K-PHOS Original can be dissolved in water. Keep in mind that this brand is different because it doesn't contain sodium. If you have trouble swallowing tablets by mouth, ask your healthcare team whether K PHOS Original is appropriate for you.
              Is potassium phosphate/sodium phosphate over the counter?
              Most brands of potassium phosphate/sodium phosphate aren't available over the counter and require a prescription from a healthcare professional. However, certain brands can be purchased over the counter. Ask your healthcare professional which product is best for you.
              Does potassium phosphate/sodium phosphate interact with any medications?
              Yes, potassium phosphate/sodium phosphate can interact with some medications. Taking this medication with antacids containing calcium, aluminum, or magnesium can prevent potassium phosphate/sodium phosphate from being absorbed. This means you might not get the full benefit of taking potassium phosphate/sodium phosphate. In addition, taking potassium phosphate/sodium phosphate with certain blood pressure medications (e.g., hydralazine, methyldopa) or with corticosteroids might put you at risk for high sodium levels in the blood (hypernatremia). Talk to your care team if you have nausea or vomiting, poor appetite, restlessness, muscle weakness, or are thirstier than usual while taking this medication.
              Can I take potassium phosphate/sodium phosphate if I have kidney problems?
              You shouldn't take potassium phosphate/sodium phosphate if your kidneys are severely damaged. Severely damaged kidneys don't work as well to get rid of potassium. Since potassium phosphate/sodium phosphate contains potassium, taking this medication if you have severe kidney disease can raise your risk of potassium buildup in your body. High potassium levels can cause fatigue, muscle weakness, nausea, and more seriously, an irregular heartbeat. If you have kidney problems, talk to your prescriber before taking this medication to see if it's safe for you.
              GoodRxEducationalIcon

              How to save using GoodRx

              Compare Prices
              1. Compare PricesSpecify your dosage and quantity to find out exactly how much you can save.
              Select your free coupon
              2. Select your free couponYou can use the displayed coupon, or compare prices at other pharmacies near you.
              Show coupon to your pharmacist
              3. Show coupon to your pharmacistPresent your printed or electronic coupon when you pick up your prescription.
              Get free couponLearn more
              warings-icon

              What are the 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.

              risk-warning

              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.

                risk-warning

                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.

                dosage

                Potassium phosphate/sodium phosphate dosage forms

                The average cost for 120 tablets of 250mg of Potassium phosphate/sodium phosphate is $21.18 with a free GoodRx coupon. This is 69.43% off the average retail price of $69.29.
                tablet
                Tablet
                DosageQuantityPrice as low asPrice per unit
                250mg120 tablets$21.18$0.18

                Typical dosing 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.

                interactions

                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
                drug-cost

                How much does Potassium phosphate/sodium phosphate cost?

                To access savings, use a GoodRx coupon and pay just a fraction of the retail price.
                K-Phos Neutral (brand)
                GoodRx lowest price

                $20.56

                (save 83.06%)
                Potassium phosphate/sodium phosphate (generic)
                GoodRx lowest price

                $20.56

                (save 70.32%)
                View prices & coupons
                contraindications-icon

                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

                alternatives

                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:
                $20.56 Lowest GoodRx priceView Prices
                K-Phos (potassium phosphate)
                Used for:

                • Lowering urinary pH

                $36.84 Lowest GoodRx priceView Prices

                Get savings updates for Potassium phosphate/sodium phosphate

                Receive price alerts, news, and other messages from GoodRx about Potassium phosphate/sodium phosphate and other healthcare topics and relevant savings offers.

                By signing up, I agree to GoodRx's Terms and Privacy Policy, and to receive marketing messages from GoodRx.

                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.

                View All References (6)

                MedlinePlus. (2023). Urine pH test.

                MedlinePlus. (2024). Kidney stones - self-care.

                National Institutes of Health Office of Dietary Supplements. (2021). Phosphorus: Fact sheet for consumers.

                Rising Pharma Holdings, Inc. (2024). Dibasic sodium phosphate, monobasic potassium phosphate and monobasic sodium phosphate- dibasic sodium phosphate, monobasic potassium phosphate and monobasic sodium phosphate tablet [package insert]. DailyMed.

                Saran, A. K., et al. (2022). Concerns regarding tablet splitting: A systematic review. BJGP Open.

                Zemaitis, M. R., et al. (2024). Uremia. StatPearls.

                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.
                Was this page helpful?

                Browse medications

                View All

                Research prescriptions and over-the-counter medications from A to Z, compare drug prices, and start saving.