del Valle Elisa E, Spivacow Francisco R, Negri Armando L
Instituto de Investigaciones Metabólicas, Universidad del Salvador, Buenos Aires, Argentina.
Medicina (B Aires). 2013;73(4):363-8.
Citrate is a powerful inhibitor of the crystallization of calcium salts. Hypocitraturia is a biochemical common alteration in calcium stone formation in adults and especially in children. The acid pH (systemic, tubular and intracellular) is the main determinant of citrate excretion in the urine. While the etiology of hypocitraturia is idiopathic in most patients with kidney stones, there are a number of causes for this abnormality including distal renal tubular acidosis, hypokalemia, diets rich in animal protein and / or diets low in alkali and certain drugs, such as acetazolamide, topiramate, ACE inhibitors and thiazides. Dietary modifications that benefit these patients include high intake of fluids and fruits, especially citrus, sodium and protein restriction, with normal calcium intake. Treatment with potassium citrate is effective in patients with primary or secondary hypocitraturia and acidification disorders, which cause unduly acidic urine pH persistently. Adverse effects are low and are referred to the gastrointestinal tract. While there are various preparations of citrate (potassium citrate, sodium citrate, potassium citrate, magnesium) in our country is available only potassium citrate powder that is useful to correct both the hypocitraturia and the low urinary pH and reduce markedly the recurrence of kidney stones.
枸橼酸盐是钙盐结晶的强力抑制剂。低枸橼酸尿是成人尤其是儿童钙结石形成中常见的生化改变。酸性pH值(全身、肾小管和细胞内)是尿中枸橼酸盐排泄的主要决定因素。虽然大多数肾结石患者低枸橼酸尿的病因是特发性的,但这种异常有多种原因,包括远端肾小管酸中毒、低钾血症、富含动物蛋白的饮食和/或低碱饮食以及某些药物,如乙酰唑胺、托吡酯、血管紧张素转换酶抑制剂和噻嗪类药物。对这些患者有益的饮食调整包括大量摄入液体和水果,尤其是柑橘类水果,限制钠和蛋白质摄入,同时保持正常钙摄入。枸橼酸钾治疗对原发性或继发性低枸橼酸尿及酸化障碍患者有效,这些情况会导致尿液pH值持续过度酸性。不良反应较少,主要涉及胃肠道。虽然有多种枸橼酸盐制剂(枸橼酸钾、枸橼酸钠、枸橼酸钾镁),但我国仅有枸橼酸钾粉剂,它对纠正低枸橼酸尿和低尿pH值以及显著降低肾结石复发有效。