Examples

How It Works

Orthophosphate reduces the amount of calcium in the urine. High levels of calcium in the urine can cause calcium kidney stones.

Why It Is Used

Orthophosphate may be used to treat kidney stones:

• Caused by high levels of calcium in the urine.
• Caused by low levels of phosphate in the urine (renal phosphate leak).
• For which the specific cause cannot be found.

How Well It Works

Some studies show that orthophosphate prevents kidney stones. Other studies have shown no benefit from treatment with orthophosphate. No controlled trials have been done.¹

Side Effects

Possible side effects of orthophosphate include gas and diarrhea.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Do not take orthophosphate if you have:

• Kidneys that do not function well (renal insufficiency).
• A urinary tract infection.
• Blocked urine flow.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Citations

1. Spector DA (2007). Urinary stones. In NH Fiebach et al., eds., Principles of Ambulatory Medicine, 7th ed., pp. 754–766. Philadelphia: Lippincott Williams and Wilkins.