Snidero M
Laboratorio di analisi chimico-cliniche e microbiologiche, Presidio ospedaliero, U.S.L. 5, Cividale del Friuli, Udine.
Quad Sclavo Diagn. 1987 Mar;23(1):72-91.
In relation to antiasthmatic treatment of hospitalized patients with theophyllines, results concerning: a) a retrospective analysis of plasma levels observed over a 18-month period; b) a pharmacokinetic study and consequent determination of an efficient individual posology are reported. On the 194 serum drug tests (each comprehensive of the trough and peak concentrations) evaluated, 58 (30%) entered the retrospective study, after screening by predetermined criteria. 96 out of 194 (49%) tests were eliminated because of inappropriate sample collection or irrational dosage regimen. The theophylline blood levels, distinguished by drug formulation and posology, were spread over very large ranges (coefficient of variation up to 88%, mean of 55%), so that many concentrations were subtherapeutic or potentially toxic. The kinetic study, undergone by 22 patients, was carried out by administering and intravenous test-dose of aminophylline, followed by collection of blood samples at determined times. Elimination half-life, clearance and volume of distribution were then calculated by means of the plasma theophylline concentrations and subsequently an individual optimized dosage regimen (so as to keep the blood drug levels within the 8-16 mg.l-1 range) was determined. The considerable variability of elimination rate observed among patients (extreme values of half-life and clearance differ 10-fold) mainly account for the unforeseeability of plasma levels obtainable with a given posology. Even if the factors affecting the elimination rate of theophylline (i.e. cigarette smoking, obesity, congestive heart failure, chronic obstructive pulmonary disease, pneumonia) are taken into account, the blood concentrations are frequently unforeseeable. Therefore, the monitoring of plasma levels is necessary for every patient treated with theophyllines and a pharmacokinetic study is desirable in some cases.
关于住院患者使用茶碱类药物进行抗哮喘治疗，报告了以下结果：a）对18个月期间观察到的血浆水平进行回顾性分析；b）进行药代动力学研究并随后确定有效的个体化给药方案。在评估的194次血清药物检测（每次均包括谷浓度和峰浓度）中，经预定标准筛选后，58次（30%）进入回顾性研究。194次检测中有96次（49%）因样本采集不当或给药方案不合理而被排除。根据药物剂型和给药方案区分的茶碱血药水平分布范围非常大（变异系数高达88%，平均值为55%），因此许多浓度低于治疗水平或具有潜在毒性。22名患者进行了动力学研究，通过静脉注射氨茶碱试验剂量，随后在特定时间采集血样。然后根据血浆茶碱浓度计算消除半衰期、清除率和分布容积，随后确定个体化优化给药方案（以使血药水平保持在8 - 16mg·l-1范围内）。患者之间观察到的消除率存在显著差异（半衰期和清除率的极值相差10倍），这主要解释了给定给药方案下血浆水平的不可预测性。即使考虑到影响茶碱消除率的因素（即吸烟、肥胖、充血性心力衰竭、慢性阻塞性肺疾病、肺炎），血药浓度通常仍不可预测。因此，对于每一位接受茶碱治疗的患者，监测血浆水平是必要的，在某些情况下进行药代动力学研究是可取的。
