| Popis: |
Publisher Summary Quinolone agents exhibit a bicyclic aromatic core, containing a carbon at the 8th position, yielding a true quinolone, or a nitrogen, and provide a ring system technically termed as naphthyridone. In common usage, both quinolone and naphthyridone structures are encompassed in the class descriptor “quinolone antibacterial agents.” The first generation quinolone compounds generally displayed increased Gram-negative activity over nalidixic acid, but lacked useful activity against Gram-positive cocci, Pseudomonas aeruginosa, and anaerobes. They were, however, generally well absorbed after oral administration and attained high concentrations in the urinary tract, making them useful therapeutically for treatment of urinary tract infections. In the second-generation quinolones, the piperazine ring remains relatively undisturbed, except for alkylation on the distal nitrogen or, less frequently, on the ring carbons. The second-generation compounds are characterized by good to excellent Gram-negative activity, with ciprofloxacin exhibiting the strongest Gram-negative spectrum. The third- and fourth-generation quinolones are characterized by increased structural novelty and complexity, which has resulted in new and useful characteristics. Clinafloxacin, sitafloxacin, and BAY y 3118, all of which bear a chlorine atom at C-8, are among the most potent broad-spectrum agents that have been in the development, and are the only compounds that exhibit Gram-negative activity superior to that of ciprofloxacin. These compounds, with the exception of pazufloxacin, show improved activity against S. pneumoniae compared to ciprofloxacin. The most potent of these agents are gemifloxacin and BAY y 3118, followed by clinafloxacin, sitafloxacin, moxifloxacin, and trovafloxacin. |
