Arayne M Saeed, Sultana Najma, Haroon Urooj, Hamza Erum
Department of Chemistry, University of Karachi. Karachi-75270, Pakistan.
Pak J Pharm Sci. 2007 Jul;20(3):235-43.
Enoxacin is a second-generation quinolone with increased antibacterial activity both in potency as well as in terms of broad spectrum against a wide range of clinically important pathogens over the first generation quinolones and produces its effect by inhibiting bacterial enzyme DNA gyrase. There are a number of drug interactions reported for enoxacin. On the other hand H2-receptor antagonists block gastric acid secretion and some cardiovascular effects of histamine. As the later drugs are used for a long-term therapy, they may be coadministered with other drugs. In present study in vitro release of enoxacin in presence of cimetidine, ranitidine and famotidine has been studied on a B.P. 2003 dissolution test apparatus and compared with the availability of enoxacin and H2-receptor antagonists alone. The interacting drugs were analyzed spectrophotometrically. These studies were carried out in simulated gastric juice, simulating empty stomach, simulated intestinal juice (pH 9) and buffers of pH 7.4 simulating blood pH at 37 degrees C. In order to support these interaction studies, the effect of H2-receptor antagonists on the antibacterial efficacy (MIC) of enoxacin was also studied by turbidity method and compared with parent drug against Staphylococcus aureus, Streptococcus pyogens, Streptococcus pneumoniae, Enterococcus, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis and Bacillus subtilis. On the basis of these results, it is suggested that enoxacin should be coadministered with care along with H2-receptor antagonists especially in case of ranitidine, although chances of adverse reactions are rare but decrease in MIC of enoxacin may result in delayed effect or require prolonged use of the drug.
依诺沙星是第二代喹诺酮类药物，与第一代喹诺酮类药物相比，其抗菌活性在效力和对多种临床重要病原体的广谱性方面均有所增强，它通过抑制细菌酶DNA回旋酶发挥作用。有许多关于依诺沙星药物相互作用的报道。另一方面，H2受体拮抗剂可阻断胃酸分泌以及组胺的一些心血管效应。由于这些药物用于长期治疗，它们可能会与其他药物联合使用。在本研究中，使用英国药典2003年溶出度试验装置研究了在西咪替丁、雷尼替丁和法莫替丁存在的情况下依诺沙星的体外释放情况，并与单独使用依诺沙星和H2受体拮抗剂的情况进行了比较。通过分光光度法分析相互作用的药物。这些研究在模拟胃液、模拟空腹、模拟肠液（pH 9）和pH 7.4模拟血液pH的缓冲液中于37℃下进行。为了支持这些相互作用研究，还通过比浊法研究了H2受体拮抗剂对依诺沙星抗菌效力（MIC）的影响，并与母体药物对金黄色葡萄球菌、化脓性链球菌、肺炎链球菌、肠球菌、大肠杆菌、伤寒沙门氏菌、铜绿假单胞菌、肺炎克雷伯菌、奇异变形杆菌和枯草芽孢杆菌的抗菌效力进行了比较。基于这些结果，建议依诺沙星与H2受体拮抗剂联合使用时应谨慎，尤其是与雷尼替丁联合使用时，尽管不良反应的可能性很小，但依诺沙星MIC的降低可能会导致疗效延迟或需要延长药物使用时间。
