Department of Internal Medicine, Gastroenterology Unit, University of L'Aquila, Piazza Salvatore Tommasi, 1 - Coppito, 67100 L'Aquila, Italy.
Expert Rev Gastroenterol Hepatol. 2009 Dec;3(6):585-98. doi: 10.1586/egh.09.63.
Rifaximin is a rifamycin derivative that acts by inhibiting bacterial RNA synthesis. Since it is virtually unabsorbed after oral administration, its bioavailability within the GI tract is high, with intraluminal and fecal drug concentrations largely exceeding the minimum inhibitory concentration values observed in vitro against a broad spectrum of bacteria, including Gram-positive and Gram-negative bacteria, both aerobes and anaerobes. The GI tract, therefore, represents the primary therapeutic target and the disorders in which intestinal bacteria have a pathogenic role represent the main indication. This is the case with colonic diverticular disease. As a consequence, the broad antibacterial activity of rifaximin appears to be of value in the treatment of this clinical condition. Clinical trials have provided evidence of the substantial benefit of rifaximin in diverticular disease. Indeed, available data show the efficacy of the drug in achieving symptomatic relief in patients with uncomplicated disease. A therapeutic gain of approximately 30%, compared with fiber supplementation only, can be expected after cyclic administration of rifaximin for 12 months. However, its value in the prevention of inflammatory complications of the disease needs to be further explored. Recent studies have shown some evidence of synergy between rifaximin and mesalazine and suggest that a combined treatment could be worthwhile in selected subsets of patients with diverticular disease.
利福昔明是一种利福霉素衍生物，通过抑制细菌的 RNA 合成起作用。由于口服后几乎不被吸收，因此其在胃肠道内的生物利用度很高，腔内和粪便中的药物浓度大大超过体外观察到的对广谱细菌（包括革兰氏阳性和革兰氏阴性细菌、需氧菌和厌氧菌）的最低抑菌浓度值。因此，胃肠道是主要的治疗靶点，肠道细菌具有致病性的疾病是主要的适应证。结肠憩室病就是这种情况。因此，利福昔明广泛的抗菌活性似乎对治疗这种临床病症有价值。临床试验为利福昔明在憩室病中的显著疗效提供了证据。事实上，与仅补充纤维相比，周期性给予利福昔明治疗 12 个月后，预计可获得约 30%的治疗获益。然而，其在预防疾病炎症性并发症方面的价值仍需要进一步探索。最近的研究表明，利福昔明和 5-氨基水杨酸之间存在协同作用的一些证据，并提示在特定的憩室病患者亚组中联合治疗可能是有价值的。
