Effect of Sodium Thiosulfate on Urine Chemistries of Hypercalciuric Stone Formers

The investigators study is designed as a pilot study to study the effect of STS on urine
chemistries in stone formers and normal controls. It is expected to continue for a duration
of 1 year and will have two groups: 20 normal controls, who are healthy subjects without
known kidney disease or nephrolithiasis, and 20 subjects with documented recurrent
nephrolithiasis and hypercalciuria. Patients will be recruited from Dr Goldfgarb's stone
clinic at VA Hospital and controls would be voluntary participants from NYU School of
Medicine. Subjects who are pregnant or nursing, taking alcohol or drugs, have known CKD or
are unable to give consent would be excluded from the study. Any diuretics or citrate
containing drugs would be held for a period of 2 weeks during the study period to achieve
washout of the effects of those drugs on urine chemistries. Oral STS 10mmol (10ml of 25% STS)
BID will be administered to both groups for 7 days; four 24 hour urine collections, 2 prior
and 2 at the end of the study, would be done with all participants. A diet diary would be
maintained by subjects concomitantly during the study periods. The investigators then plan to
compare the two groups in terms of urine chemistries to detect any changes in these
parameters with thiosulfate administration. Based on prior animal experiments and human
studies with STS the investigators anticipate that it would have a favorable effect on the
supersaturation of Ca oxalate/phosphate and therefore its long term use would be helpful in
preventing nephrolithiasis.

Inclusion Criteria:

Control arm: no longer recruiting

Hypercalciuria arm:

- Age 18-80 years old

- history of calcium-containing kidney stones

- no history of liver, heart or kidney disease (other than kidney stones)

- Non-pregnant, non-lactating

- Able to stop diuretics for a period of 1 week

Exclusion Criteria:

- Not able to sign consent

- Not satisfying any of the above criteria