Quinolone first-generation

Cefalexin is a first-generation cephalosporin and therefore an alternative preparation would be Zinnat tablets, which contains cefuroxime, a second-generation cephalosporin. A penicillin such as Augmentin, which contains co-amoxiclav, can be an appropriate alternative since it provides a very similar spectrum of activity. Klaricid contains clarithromycin, which is a macrolide. Utinor contains norfloxacin, which is a quinolone that is effective in uncomplicated urinary-tract infections. Rocephin contains ceftriaxone, which is a third-generation cephalosporin that is available for parenteral administration only. 

The first-generation and oldest quinolones exhibit limited gram-negative activity. Nalidixic acid and cinoxacin do not achieve systemic antibacterial levels and are thus restricted to therapy of bladder infections caused by urinary pathogens, such as E. coli and Klebsiella and Proteus spp. Although they are bactericidal agents, their use is restricted by resistance. 

Nalidixic acid is a first-generation quinolone that exhibits antibacterial activity against various gram-negative bacteria. It has been used exclusively in Japan for treatment of vibriosis and furunculoses of plasmonids. 

Oxolinic acid, a first-generation quinolone, has been authorized for use in fin fish, calves, swine, and poultry by the oral route. It may be given with the feed, the drinking water, or as a bolus. In 1991, 11.4 tons of oxolinic acid in addition to 5.7 tons of flumequine were used by the Norwegian aquaculture industry (187). 

Quinolones are divided into "generations" based on their spectrum of activity. The higher the generation, the broader the spectrum of activity. First generation UTIs Second and third generations UTIs, prostatitis, respiratory tract infections, sinusitis, infectious diarrhea, uncomplicated skin and skin structure infections, traveler s diarrhea... 

The quinolones are a family of synthetic broad-spectrum antibiotics. The first generation of the quinolones begins with the introduction of Nalidixic acid in 1962 for treatment of urinary tract infections in humans. Nalidixic acid was discovered by George Lesher and co-workers. 

The fluorinated quinolones are generally more potent and less toxic than the first-generation agents. Agents containing a piperazine group at the C-7 position, such as ciprofloxacin and norfloxacin, are useiul in the treatment of pseudomonal infections. The fluoroquinolones inhibit bacterial topoisomerase II (predominantly) and topoisomerase IV. 

E coli, Klebsiella, Proteus Cephalosporin (first- or second- generation),2 TMP-SMZ1 Quinolone,3 aminoglycoside5... 

E coli, klebsiella, proteus Cephalosporin (first- or second-generation), TMP-SMZ Quinolone, aminoglycoside... 

As far as synthetic agents were concerned, isoniazid (a pyridine hydrazide structure) was found to be effective against human tuberculosis in 1952, and in 1962 nalidixic acid (Fig. 10.74) (the first of the quinolone antibacterial agents) was discovered. A second generation of this class of drugs was introduced in 1987 with ciprofloxacin (Fig. 10.74). 

Nalidixic acid was first introduced in therapy in 1963, about 15 years later a new generation of quinolones with broader spectrum of activity appeared the fluoroquinolones since then about 6000 new analogs have been disclosed and about 20 derivatives are marketed or in advanced development. 

Fierens, C. Hillaert, S. Van den Bossche, W. The qualitative and quantitative determination of quinolones of first and second generation by capillary electrophoresis. J. Pharm. Biomed. Anal. 2000, 22, 763 772. 

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