Biochemical effects in patients with calcium oxalate stone disease during combined treatment with bendroflumethiazide and magnesium oxide.

Thirteen patients with calcium oxalate stone disease were treated with 2.5 mg bendroflumethiazide and 200 mg magnesium oxide twice daily for 1 year, and the effects on serum and urine constituents were evaluated. Serum magnesium and potassium decreased, whereas urate increased during treatment. The association of decreased urinary calcium and increased urinary magnesium resulted in a reduced Ca/Mg quotient and apparently a lower risk of forming urine supersaturated with calcium oxalate. Combined treatment with a thiazide and magnesium appears to alter the composition of urine in a way that might be more favourable than treatment with either substance alone.