Enhancement of Urinary Citrate in Oxalate Stone Formers by the Intake of Alkaline Salts. In: Smith LH, Robertson WG, Finlayson B, editors. Urolithiasis. Boston: Springer US; 1981. pp. 881-4. [DOI: 10.1007/978-1-4684-8977-4_141]

Management of primary hyperoxaluria: efficacy of oral citrate administration

The prognosis of primary hyperoxaluria (PH) is not only related to endogenous oxalate production and the response (if any) to pyridoxine (in type I), but is greatly influenced by extrarenal factors like dehydration. The earlier the diagnosis of PH, the better the chances of improving the prognosis in individual patients. Measures to enhance the solubility of calcium oxalate are important. Besides ensuring at all times a generous fluid intake (> 2 l/m2), administration of alkali citrate (0.15 g/kg), which has not been advocated so far in PH, appears very promising. We studied the effect of sodium citrate in six patients with PH. Mean urinary citrate excretion (mmol/day per 1.73 m2) without oral citrate was very low (0.57) and rose to 2.49 with citrate administration. This was accompanied by a significant decrease in the calcium oxalate saturation (calculated by equil 2) from 11.7 to 6.9 (P < 0.05). Treatment in five patients over 10-36 months resulted in improved (1) or stabilized (4) renal function and reduced passage of stones. Additional measures include restriction of salt and of oxalate-rich food. We conclude that long-term administration of alkali citrate is beneficial in patients with PH.

The influence of citrate on the duodenal absorption of calcium in the rat

Using in situ perfusion in the rat, we studied the duodenal bidirectional fluxes (LP, lumen-to-plasma; PL, plasma-to-lumen) and the net absorption of calcium (Ca) at progressive molar citrate:Ca ratios (1:1, 2.1:1, 8.5:1) and three pH levels (pH 5.0, 6.25, 7.0) of the Ca-containing (4 mmol/liter) perfusion solution. Rats perfused with pH-adjusted, citrate-free solutions served as controls. LP-flux and net calcium absorption (net CaA) fell dose-dependently with increasing citrate concentrations. Also, at a given citrate:Ca ratio, LP-flux and net CaA fell with increasing pH of the perfusion solution. PL-fluxes did not change from control values, irrespective of the composition of the perfusion solution. The concomitant serum Ca and parathyroid hormone levels as well as blood pH and bicarbonate, were largely unchanged under any of the citrate-containing perfusion solutions. In conclusion, citrate inhibits duodenal CaA of the rat pH- and dose-dependently, without changing intestinal Ca secretion. This effect is not related to changes in the acid-base status or to suppressed parathyroid gland function of the animals and may be best explained by dose- and pH-dependent intraluminal complex formation between Ca and citrate.

Metabolic disorders in patients with calcium urolithiasis

In the last two decades, intensive research work has been done in the field of urolithiasis. Due to improved and extended diagnostic methods, it has been recognized that metabolic disturbances play an important role in stone disease.