Cephalosporins second generation

To prevent development of resistance and promote synergy, inhaled tobramycin or colistin is usually added to an oral fluoroquinolone for P. aeruginosa coverage.1,3 Methicillin-sensitive S. aureus (MSSA) may be treated with oral amoxiciUin-clavulanic acid, dicloxacillin, first- or second-generation cephalosporins, trimethoprim-sulfamethoxazole, or clindamycin, depending on sensitivity. Likewise, methiciUin-resistant S. aureus (MRSA) may be treated with oral trimethoprim-sulfamethoxazole, clindamycin, minocycline, or linezolid. H. influenzae often produces... 

BLIC, /5-lactamase inhibitor combination BL/BLI, jS-lactamase/jS-lactamase inhibitor FGC, first-generation cephalosporin MIC, minimal inhibitory concentration PRP, penicillinase-resistant penicillin SGC, second-generation cephalosporin TGC, third-generation cephalosporin. Penicillinase-resistant penicillin nafcillin or oxacillin. 

Second-generation cephalosporins—IV cefuroxime po cefaclor, cefditoren, cefprozil, cefuroxime axetil, and loracarbef. Third-generation cephalosporins—po cefdinir, cefixime, cefetamet, cefpodoxime proxetil, and ceftibuten. 

Serious infections requiring intravenous antimicrobial therapy can be treated with a /S-lactam//S-lactamase inhibitor combination or second-generation cephalosporin with activity against anaerobes (cefoxitin). 

Treatment options for patients requiring intravenous therapy include /J-lactam-/3-lactamase inhibitors (ampicillin-sulbactam or piperacillin-tazobactam), second-generation cephalosporins with antianaerobic activity (cefoxitin), and carbapenems. 

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. 

Cefuroxime is a second-generation cephalosporin with enhanced activity against Haemophilus influenzae, a Gram-negative organism. Side-effects include nausea, vomiting and headache. 

Cefuroxime is a second-generation cephalosporin. Orally, cefuroxime is available as the prodrug, cefuroxime axetil. Cefuroxime is very well absorbed from the gastrointestinal tract and widely distributed in the body. 

Second-generation cephalosporins (cefuroxime, cefamandole, cefoxitin, cefotetan, cefaclor, and others) are characterized by high activity with respect to Gram-positive microorganisms that are resistant to beta-lactamase action. They do not have a noticible effect on enterococci. 

Second-generation cephalosporins (cefnroxime, cefamandole, cefonicid, ceforanide) are characterized by more expressed activity with respect to Gram-negative bacteria in comparison... 

Cefoxitin and cefotetan, which are cephamicins and differ from other cephalosporins principally in the presence of a methoxy group at position 7 of the cephalosporanic system, which significantly increases their resistibility with respect to beta-lactamases, belong to the second-generation cephalosporins. 

In lower UTI it is essential to choose an agent that achieves a high concentration in urine, e.g. nitrofurantoin or norfloxacin. In a patient with fever, an upper UTI can be expected (pyelonephritis bacteremia) and therefore an agent with adequate concentrations in blood and urine should be given, e.g. the second generation cephalosporin cefurox-ime. When urosepsis develops (high fever, chills... 

Obstetric infections can be treated with penicillin-beta-lactamase inhibitors such as amoxicillin-clavulanic acid, with extended spectrum penicillins (with or without beta-lacamase inhibitors if justified by local resistance surveillance data), with a first or second generation cephalosporin combined with metronidazole. In severe cases of streptococcal infection high doses of penicillin in combination with clindamycin is the treatment of choice. In amnionitis, maternal morbidity resolves with delivery. In endometritis, antibiotics should be stopped after the... 

In endophtalmitis, culture results of the vitreous aspirate can guide specific therapy. Periorbital cellulitis is treated with amoxi/ampicillin plus beta-lactamase inhibitor or a second generation cephalosporin. 

Loracarbef Lorabid) is a synthetic p-lactam antibiotic of the carbacephem class. The chemical structure of loracarbef is similar to that of cefaclor. Selected pharmacokinetic information appears in Table 45.2. Lora-carbef s spectrum of antibacterial activity resembles those of the second-generation cephalosporins. Comparative clinical trials reveal similar outcomes in patients treated with cefaclor, cefprozil, and loracarbef. 

Mechanism of Action A second-generation cephalosporin that binds to bacterial cell membranes and inhibits cell wall synthesis. Therapeutic Effect Bactericidal. Pharmacokinetics Well absorbed from the GI tract. Protein binding 25%. Widely distributed. Primarily excreted unchanged in urine. Moderately removed by hemodialysis. Half-life 0.6-0.9 hr (increased in impaired renal function). 

Mectianism of Action A second-generation cephalosporin that binds to bacterial cell... 

Cephalosporins are -lactam antibiotics that block microbial cell wall synthesis. The original cephalosporin. Cephalosporin C, has only weak antibiotic activity. Therefore much more powerful second generation cephalosporins were developed by side-chain modification. Modifications at Cl are most effective but modifications at position 3 are also important so as to increase in vivo activity. Synthesis of the second generation cephalosporin cefuroxime requires the replacement of the C3 acetoxy side-chain of the precursor with a caibamate group. Chemical methods proceed via a hydroxylated intermediate which causes problems due to a tendency to lactonise at low pHs. Therefore development of a biocatalysis step was initiated in order to achieve selective reaction nnder mild conditions. 

Members of the second-generation cephalosporins include cefaclor, cefamandole, cefonicid, cefuroxime, cefprozil, loracarbef, and ceforanide and... 

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