Hendeles L, Weinberger M
Pharmacotherapy. 1983 Jan-Feb;3(1):2-44. doi: 10.1002/j.1875-9114.1983.tb04531.x.
Theophylline is a bronchodilator and respiratory stimulant that is effective in the treatment of acute and chronic asthma, Cheyne-Stokes respirations, and apnea/bradycardia episodes in newborns. It is also used as an adjunct in the treatment of congestive heart failure and acute pulmonary edema, but it has no established efficacy in patients with chronic irreversible airways obstruction. Benefits and risks from theophylline relate directly to serum concentration, which is a function of both dose and elimination characteristics of the drug in an individual patient. When used to treat acute symptoms, an initial loading dose based on a mean volume of distribution is required to rapidly obtain maximum bronchodilator effect. Because of large interpatient differences in elimination, constant intravenous infusion rates for continued therapy must be guided by monitoring serum theophylline concentration at intervals until a steady-state serum concentration is reached within the 10-20 micrograms/ml therapeutic range. Intravenous, oral or rectal solutions and plain uncoated tablets are appropriate for acute therapy, while reliably absorbed slow-release formulations offer therapeutic advantages for the management of chronic asthma, particularly in patients with rapid elimination. Dosage for long-term therapy is determined by starting with low doses that allow virtually complete acceptance of the medication followed by gradual increases, if tolerated, at three day intervals until mean age-specific doses are reached. Subsequent adjustment in dosage regimens are then based upon serum concentration measurements. Most clinical laboratories now measure theophylline, and newer systems have been developed to provide emergency results within minutes at a reasonable cost. In cases of theophylline poisoning, the drug must be rapidly removed to prevent life-threatening toxicity. When serum concentrations are in excess of 60 micrograms/ml charcoal hemoperfusion dialysis may be indicated, even in the absence of obvious signs of toxicity.
茶碱是一种支气管扩张剂和呼吸兴奋剂，对治疗急慢性哮喘、潮式呼吸以及新生儿呼吸暂停/心动过缓发作有效。它还用作充血性心力衰竭和急性肺水肿治疗的辅助药物，但对慢性不可逆气道阻塞患者尚无确切疗效。茶碱的益处和风险直接与血清浓度相关，血清浓度是个体患者中药物剂量和消除特性的函数。用于治疗急性症状时，需要基于平均分布容积给予初始负荷剂量，以迅速获得最大支气管扩张效果。由于患者间消除差异较大，持续治疗的静脉输注速率必须通过定期监测血清茶碱浓度来指导，直至在10 - 20微克/毫升治疗范围内达到稳态血清浓度。静脉注射、口服或直肠溶液以及普通无包衣片剂适用于急性治疗，而可靠吸收的缓释制剂在慢性哮喘管理中具有治疗优势，尤其对于消除迅速的患者。长期治疗的剂量确定方法是，先从低剂量开始，使患者能基本完全接受药物，然后如果耐受，每隔三天逐渐增加剂量，直至达到特定年龄的平均剂量。随后的剂量方案调整则基于血清浓度测量结果。现在大多数临床实验室都能检测茶碱，并且已经开发出更新的系统，能以合理成本在数分钟内提供紧急检测结果。在茶碱中毒的情况下，必须迅速清除药物以防止危及生命的毒性。当血清浓度超过60微克/毫升时，即使没有明显的毒性迹象，也可能需要进行活性炭血液灌注透析。
