Katz R M, Rachelefsky G S, Siegel S C, Mickey R
Ann Allergy. 1983 Jan;50(1):23-6.
This study was performed to assess the need of obtaining serum theophylline (T) levels between 10--20 micrograms/ml to achieve maximum reversibility of airway obstruction in chronic childhood asthma. Twenty-seven children with daily asthma (ages 9--16 years mean 11.7) were studied to determine the serum T levels required to obtain optimal pulmonary function tests as measured by FEV1 and FEF25--75. Two parallel groups were created. Group 1 (13 subjects) received rapid release (RR) anhydrous T. Group 2 (14 subjects) received sustained release (SR) anhydrous T. The groups were identical in age, weight, height and PFT: p = values greater than or equal to .21 (t test for equivalent means). During initial titration maximal PFT's were obtained in Group 1 subjects with mean T level of 7.1 micrograms/ml and in Group 2 subjects with mean T level of 8.5 micrograms/ml. The PFT responses and theophylline dose responses of each group were not significantly different from each other. After two months of continuous high dose (10--20 micrograms/ml) therapy each subject was again titrated for dose response of PFT with serum T levels. PFT's were not significantly different from the acute studies. After continuous high dose theophylline therapy serum T levels needed (mean 11.5 micrograms/ml) to obtain the maximal PFT response were significantly higher than during the initial titration (mean 7.1 to 8.5 micrograms/ml). Maximal PFT's in many asthmatic children do not require serum T greater than or equal to 10 micrograms/ml in an acute dosage. The continuous use of high dose theophylline may lead to tolerance, thus requiring a higher theophylline dose and subsequent serum level to obtain maximal PFT.
本研究旨在评估为使儿童慢性哮喘气道阻塞达到最大程度可逆，血清茶碱（T）水平维持在10 - 20微克/毫升之间的必要性。对27名每日发作哮喘的儿童（年龄9 - 16岁，平均11.7岁）进行研究，以确定通过第一秒用力呼气容积（FEV1）和呼气流量峰值（FEF25 - 75）测量获得最佳肺功能测试所需的血清T水平。创建了两个平行组。第1组（13名受试者）接受速释（RR）无水茶碱。第2组（14名受试者）接受缓释（SR）无水茶碱。两组在年龄、体重、身高和肺功能测试方面相同：p值大于或等于0.21（均值等效性t检验）。在初始滴定期间，第1组受试者平均T水平为7.1微克/毫升时获得最大肺功能测试值，第2组受试者平均T水平为8.5微克/毫升时获得最大肺功能测试值。两组的肺功能测试反应和茶碱剂量反应彼此无显著差异。连续高剂量（10 - 20微克/毫升）治疗两个月后，再次对每个受试者进行血清T水平的肺功能测试剂量反应滴定。肺功能测试结果与急性研究无显著差异。连续高剂量茶碱治疗后，获得最大肺功能测试反应所需的血清T水平（平均11.5微克/毫升）显著高于初始滴定期间（平均7.1至8.5微克/毫升）。许多哮喘儿童在急性给药时，最大肺功能测试并不需要血清T大于或等于10微克/毫升。持续使用高剂量茶碱可能导致耐受性，因此需要更高的茶碱剂量及随后的血清水平以获得最大肺功能测试值。
