Asmus M J, Hendeles L
Department of Pharmacy Practice, College of Pharmacy, University of Florida, Gainesville, USA.
Pharmacotherapy. 2000 Feb;20(2):123-9. doi: 10.1592/phco.20.3.123.34776.
Albuterol is a 50:50 mixture of R-albuterol, the active enantiomer, and S-albuterol, which appears to be inactive in humans. The Food and Drug Administration recently approved levalbuterol, the pure R-isomer, as a preservative-free nebulizer solution. Published studies indicate that it is neither safer nor more effective than an equimolar dose of racemic albuterol (levalbuterol 1.25 mg = albuterol 2.5 mg). However, these studies were conducted in patients with stable asthma (at the top of the dose-response curve), whereas a nebulized bronchodilator most likely would be used by patients with an acute exacerbation. Because such patients, in the hospital setting, often require higher doses of albuterol, the manufacturer's recommended dose of levalbuterol is likely to be too low for rescue therapy. Levalbuterol may cost as much as 5 times more than racemic albuterol, depending on purchase method. We conclude that levalbuterol offers no advantage over albuterol but is likely to be more costly.
沙丁胺醇是活性对映体R-沙丁胺醇和S-沙丁胺醇的50:50混合物，S-沙丁胺醇在人体中似乎无活性。美国食品药品监督管理局最近批准了纯R-异构体左旋沙丁胺醇作为一种无防腐剂的雾化溶液。已发表的研究表明，它并不比等摩尔剂量的消旋沙丁胺醇更安全或更有效（左旋沙丁胺醇1.25毫克 = 沙丁胺醇2.5毫克）。然而，这些研究是在稳定期哮喘患者中进行的（处于剂量反应曲线的顶端），而雾化支气管扩张剂最有可能被急性加重期患者使用。因为在医院环境中，这类患者通常需要更高剂量的沙丁胺醇，所以制造商推荐的左旋沙丁胺醇剂量对于急救治疗可能过低。根据购买方式不同，左旋沙丁胺醇的成本可能比消旋沙丁胺醇高出5倍之多。我们得出结论，左旋沙丁胺醇相比沙丁胺醇并无优势，但可能成本更高。
