Langtry H D, Brogden R N
Adis International Limited, Auckland, New Zealand.
Drugs. 1997 Jun;53(6):973-1004. doi: 10.2165/00003495-199753060-00006.
Clarithromycin is a broad spectrum macrolide antibacterial agent active in vitro and effective in vivo against the major pathogens responsible for respiratory tract infections in immunocompetent patients. It is highly active in vitro against pathogens causing atypical pneumonia (Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp.) and has similar activity to other macrolides against Staphylococcus aureus. Streptococcus pyogenes, Moraxella catarrhalis and Streptococcus pneumoniae. Haemophilus influenzae is susceptible or intermediately susceptible to clarithromycin alone, but activity is enhanced when the parent drug and metabolite are combined in vitro. Absorption of clarithromycin is unaffected by food. More than half of an oral dose is systemically available as the parent drug and the active 14-hydroxy metabolite. Pharmacokinetics are nonlinear, with plasma concentrations increasing in more than proportion to the dosage. First-pass metabolism results in the rapid appearance of the active metabolite 14-hydroxy-clarithromycin in plasma. Clarithromycin and its active metabolite are found in greater concentrations in the tissues and fluids of the respiratory tract than in plasma. Dosage adjustments are required for patients with severe renal failure, but not for elderly patients or those with hepatic impairment. Drug interactions related to the cytochrome P450 system may occur with clarithromycin use. In addition to the standard immediate-release formulation for administration twice daily, a modified-release formulation of clarithromycin is now available for use once daily. In dosages of 500 to 1000 mg/day for 5 to 14 days, clarithromycin was as effective in the treatment of community-acquired upper and lower respiratory tract infections in hospital and community settings as beta-lactam agents (with or without a beta-lactamase inhibitor), cephalosporins and most other macrolides. Clarithromycin was similar in efficacy to azithromycin in comparative studies and is as effective as and better tolerated than erythromycin. Adverse events are primarily gastrointestinal in nature, but result in fewer withdrawals from therapy than are seen with erythromycin. Clarithromycin provides similar clinical and bacteriological efficacy to that seen with beta-lactam agents, cephalosporins and other macrolides. It offers a cost-saving alternative to intravenous erythromycin use in US hospitals and is available in both once-daily and twice-daily formulations. The spectrum of activity of clarithromycin against common and emerging respiratory tract pathogens may make it suitable for use in the community as empirical therapy of respiratory tract infections in both children and adults.
克拉霉素是一种广谱大环内酯类抗菌药物，在体外具有活性，在体内对免疫功能正常患者呼吸道感染的主要病原体有效。它在体外对引起非典型肺炎的病原体（肺炎衣原体、肺炎支原体和军团菌属）具有高度活性，对金黄色葡萄球菌、化脓性链球菌、卡他莫拉菌和肺炎链球菌的活性与其他大环内酯类药物相似。流感嗜血杆菌单独对克拉霉素敏感或中度敏感，但在体外当母体药物和代谢产物联合时活性增强。克拉霉素的吸收不受食物影响。口服剂量的一半以上以母体药物和活性14-羟基代谢产物的形式全身可用。药代动力学是非线性的，血浆浓度的增加与剂量不成比例。首过代谢导致活性代谢产物14-羟基克拉霉素在血浆中迅速出现。克拉霉素及其活性代谢产物在呼吸道组织和体液中的浓度高于血浆。严重肾衰竭患者需要调整剂量，但老年患者或肝功能损害患者不需要。使用克拉霉素可能会发生与细胞色素P450系统相关的药物相互作用。除了标准的每日两次给药的速释制剂外，现在还有克拉霉素的缓释制剂可每日一次使用。在500至1000mg/天的剂量下使用5至14天，克拉霉素在医院和社区环境中治疗社区获得性上、下呼吸道感染的效果与β-内酰胺类药物（有或无β-内酰胺酶抑制剂）、头孢菌素和大多数其他大环内酯类药物相同。在比较研究中，克拉霉素的疗效与阿奇霉素相似，与红霉素一样有效且耐受性更好。不良事件主要为胃肠道性质，但与红霉素相比，因不良事件停药的情况较少。克拉霉素提供了与β-内酰胺类药物、头孢菌素和其他大环内酯类药物相似的临床和细菌学疗效。在美国医院，它为静脉使用红霉素提供了一种节省成本的替代方案，并且有每日一次和每日两次的制剂。克拉霉素对常见和新出现的呼吸道病原体的活性谱可能使其适用于社区作为儿童和成人呼吸道感染的经验性治疗。
