Editing Kidney stone disease (section)

=== Allopurinol ===
For people with [[hyperuricosuria]] and calcium stones, [[allopurinol]] is one of the few treatments that have been shown to reduce kidney stone recurrences. Allopurinol interferes with the production of uric acid in the [[liver]]. The drug is also used in people with [[gout]] or hyperuricemia (high [[Serum (blood)|serum]] uric acid levels).<ref name=Cameron1987 /> Dosage is adjusted to maintain a reduced urinary excretion of uric acid. Serum uric acid level at or below 6&nbsp;mg/100&nbsp;mL is often a therapeutic goal. Hyperuricemia is not necessary for the formation of uric acid stones; hyperuricosuria can occur in the presence of normal or even [[hypouricemia|low serum uric acid]]. Some practitioners advocate adding allopurinol only in people in whom hyperuricosuria and hyperuricemia persist, despite the use of a urine-[[alkalinizing agent]] such as [[sodium bicarbonate]] or [[potassium citrate]].<ref name=Knudsen2007 />