Gasbarrini Antonio, Gasbarrini Giovanni, Pelosini Iva, Scarpignato Carmelo
Department of Internal Medicine, Gemelli University Hospital, Catholic University of Sacred Heart, Rome, Italy.
Digestion. 2006;73 Suppl 1:129-35. doi: 10.1159/000089788. Epub 2006 Feb 8.
Rifaximin is a non-absorbed semisynthetic rifamycin derivative with a broad spectrum of antibacterial activity including Gram-positive and Gram-negative bacteria, both aerobes and anaerobes. Although originally developed for the treatment of infectious diarrhea, the appreciation of the pathogenic role of gut bacteria in several organic and functional gastrointestinal diseases has increasingly broadened its clinical use. Being the antibiotic active against Helicobacter pylori, even towards clarithromycin-resistant strain, and being the primary resistance very rare, several investigations explored its potential use for eradication of the microorganism. Rifaximin alone proved to be effective, but even the highest dose (1,200 mg daily) gave a cure rate of only 30%. Dual and triple therapies were also studied, with the better results obtained with rifaximin-clarithromycin and rifaximin-clarithromycin-esomeprazole combinations. However, the eradication rates (60-70%) obtained with these regimens were still below the standard set by the Maastricht Consensus guidelines. Although rifaximin-based eradication therapies are promising, new antimicrobial combinations (with and without proton pump inhibitors) need to be explored in well-designed clinical trials including a large cohort of H. pylori-infected patients. The remarkable safety of rifaximin will allow high-dose regimens of longer duration (e.g. 10 or 14 days) to be tested with confidence in the hope of achieving better eradication rates. A drawback of rifaximin could be its inability to reach sufficiently high concentrations in the gastric mucus layer under and within which H. pylori is commonly located and this would likely affect eradication rate. Taking these considerations into account, bioadhesive rifaximin formulations able to better and persistently cover gastric mucosa, or combination with mucolytic agents, such as pronase or acetylcysteine, need to be evaluated in order to better define the place of this antibiotic in our therapeutic armamentarium.
利福昔明是一种不被吸收的半合成利福霉素衍生物，具有广泛的抗菌活性，包括革兰氏阳性菌和革兰氏阴性菌，兼性厌氧菌和厌氧菌。尽管最初开发用于治疗感染性腹泻，但随着对肠道细菌在多种器质性和功能性胃肠道疾病中致病作用的认识不断深入，其临床应用范围也日益扩大。作为一种对幽门螺杆菌有效的抗生素，甚至对克拉霉素耐药菌株也有效，且主要耐药情况非常罕见，多项研究探讨了其根除该微生物的潜在用途。单独使用利福昔明已被证明有效，但即使是最高剂量（每日1200毫克），治愈率也仅为30%。也对双联和三联疗法进行了研究，利福昔明-克拉霉素和利福昔明-克拉霉素-埃索美拉唑联合使用取得了更好的效果。然而，这些方案获得的根除率（60%-70%）仍低于马斯特里赫特共识指南设定的标准。尽管基于利福昔明的根除疗法很有前景，但需要在精心设计的临床试验中探索新的抗菌联合方案（有无质子泵抑制剂），纳入大量幽门螺杆菌感染患者队列。利福昔明显著的安全性将使高剂量、更长疗程（如10或14天）的方案能够放心测试，以期实现更高的根除率。利福昔明的一个缺点可能是它无法在幽门螺杆菌通常所在的胃黏液层及其内部达到足够高的浓度，这可能会影响根除率。考虑到这些因素，需要评估能够更好且持久覆盖胃黏膜的生物黏附性利福昔明制剂，或与溶黏液剂（如链霉蛋白酶或乙酰半胱氨酸）联合使用，以便更好地确定这种抗生素在我们治疗手段中的地位。
