Rogers R J, Kalisker A, Wiener M B, Szefler S J
J Pediatr. 1985 Mar;106(3):496-501. doi: 10.1016/s0022-3476(85)80690-9.
During routine monitoring of hospitalized children with asthma receiving a sustained-release theophylline formulation, we frequently observe unpredictable fluctuations in serum theophylline concentration (STC). We evaluated eight asthmatic patients (ages 4 to 17 years) with inconsistent STCs to determine the cause of this phenomenon. Only minimal variation in STC and therefore theophylline clearance was noted during a 24-hour period of continuous intravenous aminophylline infusion. However, marked variability in STC was observed when measured every 2 hours for 48 hours after 6 days of continuous therapy orally. In addition, the time required to reach peak and trough STCs varied from dose to dose. Inasmuch as clearance was shown to be constant, the variability was attributed to inconsistent theophylline absorption. Unpredictable fluctuations of STC secondary to variable absorption from this sustained-release theophylline preparation may occur in certain patients. Appreciation of this potential variability is necessary for the proper interpretation of STC measurements and subsequent dosage adjustment.
在对接受缓释茶碱制剂治疗的住院哮喘患儿进行常规监测时，我们经常观察到血清茶碱浓度（STC）出现不可预测的波动。我们评估了8例STC不稳定的哮喘患者（年龄4至17岁），以确定这种现象的原因。在持续静脉输注氨茶碱24小时期间，仅观察到STC及因此的茶碱清除率有极小变化。然而，在连续口服治疗6天后，每2小时测量一次，持续48小时，观察到STC有明显变化。此外，达到STC峰值和谷值所需的时间因剂量而异。由于已证明清除率是恒定的，这种变化归因于茶碱吸收不一致。某些患者可能会出现因这种缓释茶碱制剂吸收可变导致的STC不可预测波动。认识到这种潜在的变异性对于正确解释STC测量结果及随后的剂量调整是必要的。
