Neu H C, Chin N X, Gu J W
Department of Medicine College of Physicians & Surgeons, Columbia University, New York.
J Antimicrob Chemother. 1992 Jul;30 Suppl A:83-94. doi: 10.1093/jac/30.suppl_a.83.
RP 59500 is a 30:70 mixture of RP 57669 and RP 54476. The activity of RP 59500 and its two components against Gram-positive and Gram-negative organisms was compared with that of clarithromycin, roxithromycin, azithromycin and rokitamycin. RP 59500 inhibited 90% of erythromycin-susceptible and resistant Staphylococcus aureus and coagulase-negative staphylococci at less than or equal to 1 mg/L (range 0.06-2 mg/L). Both inducibly and constitutively-resistant strains of S. aureus, as well as strains resistant to rifampicin, gentamicin and ciprofloxacin, were inhibited. Streptococcus pyogenes, including erythromycin-resistant isolates, and group C and G streptococci were inhibited by 0.5 mg/L. Streptococcus pneumoniae and viridans group streptococci were inhibited by 1 mg/L. The MIC90 was 4 mg/L for Haemophilus influenzae and 1 mg/L for Moraxella catarrhalis. RP 59500 did not inhibit Enterobacteriaceae or Pseudomonas aeruginosa. The activity of RP 59500 against streptococci was less than that of the four other macrolides. Clostridium perfringens strains were highly susceptible, as were Bacteroides spp. RP 59500, when combined with ciprofloxacin, cefotaxime or gentamicin, did not have altered activity against susceptible species or alter the activity of the other component of the combination against susceptible species. MBCs in serum were increased two- to four-fold for S. pyogenes, S. pneumoniae and S. aureus, compared with MBCs in broth, but RP 59500 was as active at pH 6 as at pH 7, and there was not an appreciable inoculum effect. RP 59500 has potential use as an agent against inducibly and constitutively erythromycin-resistant isolates of Gram-positive species and selected anaerobic organisms.
RP 59500是RP 57669和RP 54476按30:70的比例混合而成。将RP 59500及其两种成分对革兰氏阳性菌和革兰氏阴性菌的活性与克拉霉素、罗红霉素、阿奇霉素和罗他霉素进行了比较。RP 59500在浓度小于或等于1mg/L（范围为0.06 - 2mg/L）时可抑制90%的对红霉素敏感和耐药的金黄色葡萄球菌及凝固酶阴性葡萄球菌。金黄色葡萄球菌的诱导型和组成型耐药菌株，以及对利福平、庆大霉素和环丙沙星耐药的菌株均受到抑制。化脓性链球菌，包括对红霉素耐药的分离株，以及C组和G组链球菌在0.5mg/L浓度下受到抑制。肺炎链球菌和草绿色链球菌在1mg/L浓度下受到抑制。流感嗜血杆菌的MIC90为4mg/L，卡他莫拉菌的MIC90为1mg/L。RP 59500不抑制肠杆菌科细菌或铜绿假单胞菌。RP 59500对链球菌的活性低于其他四种大环内酯类药物。产气荚膜梭菌菌株高度敏感，拟杆菌属也是如此。RP 59500与环丙沙星、头孢噻肟或庆大霉素联合使用时，对敏感菌的活性未改变，也未改变联合用药中其他成分对敏感菌的活性。与肉汤中的MBC相比，化脓性链球菌、肺炎链球菌和金黄色葡萄球菌在血清中的MBC增加了2至四倍，但RP 59500在pH 6时与在pH 7时活性相同，且没有明显的接种量效应。RP 59500有潜力作为一种药物用于对抗革兰氏阳性菌的诱导型和组成型红霉素耐药分离株以及某些厌氧菌。
