Mazkereth R, Laufer J, Jordan S, Pomerance J J, Boichis H, Reichman B
Department of Neonatology, Chaim Sheba Medical Center, Tel Hashomer, Israel.
Am J Perinatol. 1997 Jan;14(1):45-9. doi: 10.1055/s-2007-994095.
Xanthines are frequently being used in the management of premature babies. Studies in adult subjects have demonstrated a diuretic effect of aminophylline due to the inhibition of solute reabsorption in various segments of the nephron. We evaluated the effects of aminophylline on the developing kidney. Nineteen premature infants, with a mean +/- SD gestational age of 31.1 +/- 2.8 weeks and mean birth weight of 1481 +/- 454 g were studied at mean age of 4.5 +/- 4.0 days before and after a 20-minute loading infusion of 6 mg/kg aminophylline, followed by maintenance therapy at a dose of 2 mg/kg every 12 hours. A marked diuresis occurred immediately after the loading dose, the ratio of urinary output to water intake increased from 0.58 +/- 0.36 to 1.19 +/- 0.65. Concomitantly, the fractional excretion of sodium increased from 2.7 +/- 2.6% to 5.7 +/- 4.4% and that of potassium rose from 21 +/- 19% to 31 +/- 21%. Urinary calcium and uric acid excretion were also enhanced: calcium to creatinine ratio rose from 0.31 +/- 0.29 to 0.60 +/- 0.54 and uric acid to creatinine ratio increased from 2.5 +/- 1.5 to 3.8 +/- 2.0. Tubular reabsorption of phosphorus (TRP) was not affected. Most of the effects were no longer evident after 24 hours, despite continuing aminophylline maintenance therapy. In premature infants the aminophylline loading dose, but not maintenance therapy, affected renal functions. Because heart rate, blood pressure, and creatinine clearance did not change, it appears that aminophylline acts directly on tubular reabsorptive functions.
黄嘌呤类药物常用于早产儿的治疗。针对成年受试者的研究表明，氨茶碱具有利尿作用，这是由于它抑制了肾单位各节段的溶质重吸收。我们评估了氨茶碱对发育中的肾脏的影响。研究了19名早产儿，其平均胎龄为31.1±2.8周（均值±标准差），平均出生体重为1481±454克，研究时的平均年龄为4.5±4.0天，在静脉输注6毫克/千克氨茶碱20分钟进行负荷给药前和给药后，随后每12小时以2毫克/千克的剂量进行维持治疗。负荷剂量给药后立即出现明显的利尿作用，尿量与水摄入量的比值从0.58±0.36增加到1.19±0.65。与此同时，钠的排泄分数从2.7±2.6%增加到5.7±4.4%，钾的排泄分数从21±19%增加到31±21%。尿钙和尿酸排泄也增加：钙与肌酐的比值从0.31±0.29增加到0.60±0.54，尿酸与肌酐的比值从2.5±1.5增加到3.8±2.0。磷的肾小管重吸收（TRP）未受影响。尽管继续进行氨茶碱维持治疗，但24小时后大多数作用不再明显。在早产儿中，氨茶碱的负荷剂量而非维持治疗影响肾功能。由于心率、血压和肌酐清除率没有变化，似乎氨茶碱直接作用于肾小管重吸收功能。
