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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.


(poh-TASS-ee-um ACID FOSS-fate)



This medication makes the urine more acidic. It is used to prevent formation of calcium kidney stones and to reduce odor and skin irritation caused by high ammonia urine. It may also be used with certain antibiotics to make them more effective.

How To Use

For best results, soak tablets in a full glass of water for 3 to 5 minutes. Stir and drink. This is usually taken 4 times per day (after meals and at bedtime) with a full glass (8 oz or 240 ml) of water. Take this medication as prescribed. Do not increase your dose or take this more often without your doctor's approval.

Side Effects

Stomach upset, loose stools or headache may occur the first few days as your body adjusts to the medication. If these effects continue or become bothersome, inform your doctor. Notify your doctor if you develop: nausea, vomiting, stomach pain, fluid retention, convulsions, unusual weakness, mental confusion, dizziness, muscle cramps, a rapid or irregular heart- beat, breathing trouble, tingling or numbness of the hands or feet. When this medication is first started, there is a chance an old kidney stone may be passed. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor if you have: kidney problems, heart disease, liver disease, Addison's disease, high blood pressure, any allergies, a sodium (salt)-restricted diet (or if you use a salt substitute). This medication should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. Since small amounts of this medication are found in breast milk, consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of any over-the-counter or prescription medication you may take, including: aspirin, water pills, potassium supplements, salt substitutes, antacids, steroids, high blood pressure drugs. Avoid antacids while taking this medication since they may prevent its absorption. If necessary, space dosing of the medication and the antacid as far apart as possible. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately.


Laboratory tests may be done periodically while taking this medication to monitor its effectiveness and prevent side effects.

Missed Dose

If you miss a dose, take it as soon as remembered; do not take it if it is near the time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 59 and 86 degrees F (15 to 30 degrees C) away from heat, light and moisture. Do not store in the bathroom.