Potassium Phosphate, Monobasic

INDICATONS AND USAGE For use in patients with elevated urinary pH. K-PHOS® ORIGINAL 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.

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 and hyperkalemia.

General This product contains potassium and should be used with caution if regulation of this element is desired. Occasionally, some individuals may experience a mild laxative effect during the first few days of phosphate therapy. If laxation persists to an unpleasant degree, reduce the daily dosage until this effect subsides or, if necessary, discontinue the use of this product. Caution should be exercised when prescribing this product in the following conditions: Cardiac disease (particularly in digitalized patients); severe adrenal insufficiency (Addison's disease); acute dehydration; severe renal insufficiency or chronic renal disease; extensive tissue breakdown (such as severe burns); myotonia congenita; hypoparathyroidism; and acute pancreatitis. Rickets may benefit from phosphate therapy, but caution should be exercised. High serum phosphate levels may increase the incidence of extra-skeletal calcification. Information for Patients Patients with kidney stones may pass old stones when phosphate therapy is started and should be warned of this possibility. Patients should be advised to avoid the use of antacids containing aluminum, calcium, or magnesium, which may prevent the absorption of phosphate. To assure against gastrointestinal injury associated with oral ingestion of concentrated potassium salt preparations, patients should be instructed to dissolve tablets completely in an appropriate amount of water before taking. Laboratory Tests Careful monitoring of renal function and serum calcium, phosphorus and potassium may be required at periodic intervals during potassium phosphate therapy. Other tests may be warranted in some patients, depending on conditions. Drug Interactions The use of antacids containing magnesium, calcium, or aluminum in conjunction with phosphate preparations may bind the phosphate and prevent its absorption. Potassium-containing medications or potassium-sparing diuretics may cause hyperkalemia when used concurrently with potassium salts. Patients should have serum potassium level determinations at periodic intervals. Concurrent use of salicylates may lead to increased serum salicylate levels since excretion of salicylates is reduced in acidified urine. Serum salicylate levels should be closely monitored to avoid toxicity. Carcinogenesis, Mutagenesis, Impairment of Fertility No long-term or reproduction studies in animals or humans have been performed with K-PHOS® ORIGINAL to evaluate its carcinogenic, mutagenic, or impairment of fertility potential. Pregnancy Teratogenic Effects Pregnancy Category C Animal reproduction studies have not been conducted with K-PHOS® ORIGINAL. 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. Nursing Mothers It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when this product is administered to a nursing woman.

Gastrointestinal upset (diarrhea, nausea, stomach pain, and vomiting) may occur with the use of potassium phosphate. Also, bone and joint pain (possible phosphate-induced osteomalacia) could occur. The following adverse effects may be observed with potassium administration: irregular heartbeat; dizziness; mental confusion; weakness or heaviness of legs; unusual tiredness; muscle cramps; numbness, tingling, pain, or weakness in hands or feet; numbness or tingling around lips; shortness of breath or troubled breathing.

The use of antacids containing magnesium, calcium, or aluminum in conjunction with phosphate preparations may bind the phosphate and prevent its absorption. Potassium-containing medications or potassium-sparing diuretics may cause hyperkalemia when used concurrently with potassium salts. Patients should have serum potassium level determinations at periodic intervals. Concurrent use of salicylates may lead to increased serum salicylate levels since excretion of salicylates is reduced in acidified urine. Serum salicylate levels should be closely monitored to avoid toxicity.

Teratogenic Effects Pregnancy Category C Animal reproduction studies have not been conducted with K-PHOS® ORIGINAL. 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.

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when this product is administered to a nursing woman.

ACTIONS K-PHOS® ORIGINAL is a highly effective sodium-free urinary acidifier.