Preminger G M, Sakhaee K, Pak C Y
Department of Internal Medicine, Southwestern Medical School, Dallas, Texas.
J Urol. 1988 Feb;139(2):240-2. doi: 10.1016/s0022-5347(17)42374-3.
Alkali therapy is used commonly to prevent recurrent stone formation in patients with distal renal tubular acidosis. We compared the effects of potassium citrate to those of sodium citrate in 6 well defined cases of incomplete distal renal tubular acidosis. The patients were studied during a control phase, during potassium citrate treatment (80 mEq. per day) and during sodium citrate treatment (80 mEq. per day) chosen in random order. Potassium citrate caused a decrease in urinary calcium and a significant increase in urinary citrate that resulted in a significant decrease in the urinary saturation of calcium oxalate. It did not alter the saturation of brushite and sodium urate. However, while sodium citrate also was able to increase the urinary citrate level, there was no decrease in the urinary calcium (owing to the increased sodium load). Thus, the urinary saturation of calcium oxalate did not decrease as much as with potassium citrate and the saturation of brushite increased significantly. Moreover, the urinary saturation of sodium urate increased significantly owing to the enhanced sodium excretion. The results suggest that potassium citrate therapy may retard the crystallization of calcium oxalate and may not cause calcium phosphate crystallization. In contrast, sodium citrate may have no effect or it sometimes may accentuate the crystallization of calcium salts. Thus, our study supports the potential clinical advantage of potassium citrate therapy over sodium alkali treatment in patients with incomplete distal renal tubular acidosis and recurrent calcium nephrolithiasis.
碱疗法常用于预防远端肾小管酸中毒患者复发性结石的形成。我们在6例明确诊断的不完全性远端肾小管酸中毒患者中比较了柠檬酸钾和柠檬酸钠的效果。患者按随机顺序在对照期、柠檬酸钾治疗期（每天80毫当量）和柠檬酸钠治疗期（每天80毫当量）接受研究。柠檬酸钾使尿钙减少，尿枸橼酸盐显著增加，导致草酸钙的尿饱和度显著降低。它没有改变磷酸氢钙和尿酸钠的饱和度。然而，虽然柠檬酸钠也能够增加尿枸橼酸盐水平，但尿钙没有减少（由于钠负荷增加）。因此，草酸钙的尿饱和度没有像使用柠檬酸钾时那样降低，并且磷酸氢钙的饱和度显著增加。此外，由于钠排泄增加，尿酸钠的尿饱和度显著增加。结果表明，柠檬酸钾疗法可能会延缓草酸钙结晶，并且可能不会导致磷酸钙结晶。相比之下，柠檬酸钠可能没有效果，或者有时可能会加剧钙盐结晶。因此，我们的研究支持在不完全性远端肾小管酸中毒和复发性钙肾结石患者中，柠檬酸钾疗法相对于钠碱治疗具有潜在的临床优势。
