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K-Phos No. 2

Generic: Potassium Phosphate, Monobasic and Sodium Phosphate, Monobasic, Anhydrous

Verified·Apr 23, 2026
Manufacturer
Beach
NDC
0486-1134
RxCUI
209224
Route
ORAL
ICD-10 indication
R82.91

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About K-Phos No. 2

What is this medication? K-Phos No. 2 is a prescription medication primarily used to make the urine more acidic. It contains a combination of potassium acid phosphate and sodium acid phosphate. By lowering the pH level of the urine, this medication helps prevent the formation of specific types of kidney stones, particularly calcium stones, which are more likely to develop in an alkaline environment.

In addition to stone prevention, this medication may be used to enhance the effectiveness of certain antibiotics used to treat urinary tract infections. It can also serve as a phosphorus supplement for patients who have low levels of phosphate in their blood. Patients are typically advised to consume plenty of water while taking this medication to support kidney health and help flush the system.

Copay & patient assistance

Detailed copay and financial assistance information is not publicly available for this medication at this time. Please consult your pharmacist or the manufacturer's official patient support program for more details.

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Prescribing information

From the FDA-approved label for K-Phos No. 2. Official source: DailyMed (NLM) · Label effective Feb 23, 2023

Indications and usage
INDICATONS AND USAGE K-PHOS® No. 2 is a highly effective urinary acidifier for use in patients with elevated urinary pH. This product helps keep calcium soluble and reduces odor and rash caused by ammoniacal urine. Also, by acidifying the urine, it increases the antibacterial activity of methenamine mandelate and methenamine hippurate.
Dosage and administration
DOSAGE AND ADMINISTRATION One tablet four times daily with a full glass of water. When the urine is difficult to acidify, administer one tablet every two hours not to exceed 8 tablets in a 24-hour period.
Contraindications
CONTRAINDICATIONS This product is contraindicated in patients with infected phosphate stones, in patients with severely impaired renal function (less than 30% of normal) and in the presence of hyperphosphatemia.
Drug interactions
Drug Interactions The use of antacids containing magnesium, aluminum, or calcium in conjunction with phosphate preparations may bind the phosphate and prevent its absorption. Concurrent use of antihypertensives, especially diazoxide, guanethidine, hydralazine, methyldopa, or rauwolfia alkaloid; or corticosteroids, especially mineralocorticoids or corticotropin, with sodium phosphate may result in hypernatremia. Potassium-containing medications or potassium-sparing diuretics may cause hyperkalemia when used wi t h potassium phosphate. Patients should have serum potassium level determinations at periodic intervals. Plasma levels of salicylates may be increased since salicylate excretion is decreased in acidified urine. Administration of monobasic phosphates to patients stabilized on salicylates may lead to toxic salicylate levels.
Adverse reactions
ADVERSE REACTIONS Gastrointestinal upset (diarrhea, nausea, stomach pain and vomiting) may occur with phosphate therapy. Also, bone and joint pain (possible phosphate-induced osteomalacia) could occur. The following adverse effects may be observed (primarily from sodium or potassium): headaches; dizziness; mental confusion; seizures; weakness or heaviness of legs; unusual tiredness or weakness; muscle cramps; numbness, tingling, pain, or weakness of hands or feet; numbness or tingling around lips; fast or irregular heartbeat; shortness of breath or troubled breathing; swelling of feet or lower legs; unusual weight gain; low urine output; unusual thirst.
Use in pregnancy
Pregnancy Teratogenic Effects Pregnancy Category C Animal reproduction studies have not been conducted with K-PHOS® No. 2. It is also not known whether this product can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. This product should be given to a pregnant woman only if clearly needed.

Label text is reproduced as-is from the FDA-approved label. We do not paraphrase, summarize, or omit. Content above is for informational purposes only and is not medical advice. Always consult your prescribing clinician or pharmacist before making decisions about your medication.

Conditions we've indexed resources for

Click a condition to see copay cards, grants, and PA rules specific to it. For the full list of FDA-approved indications, see Prescribing information above.

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How this page is sourced

  • Drug identity verified against openFDA NDC Directory.
  • Label text (when shown) originates from NLM DailyMed.
  • Copay and assistance URLs verified periodically; if you hit a broken link, tell us.