Cephalosporins Aminoglycosides

Acute First-generation cephalosporin Aminoglycoside plus ampicillin if severe infection... 

The severity of aminoglycoside nephrotoxicity is additive with that of vancomycin, polymixin, gallium, furosemide, enflurane, cisplatin, and cephalosporins. Aminoglycoside nephrotoxicity is synergistic with that of amphotericin B and cyclosporine. 

The microorganisms were identified using various bacterium growth media ( HiMedia , India). The sensitivity of microorganisms to antibiotics, such as cephalosporin, aminoglycoside, tetracycline and fluorochinolone, was evaluated by diffusion in the agar gel. 

The resistance mechanisms that cause the inactivation of penicillins, cephalosporins, aminoglycosides, macrolides and tetracyclines do not apply to fluoroquinolones, and there is therefore no cross-resistance between quinolones and other antibiotics. 

Cephalosporins Aminoglycosides Antineoplastic agents Nitrosoureas Cisplatin and analogs Radiographic contrast agents Halogenated hydrocarbons Chlorotriiluoroethylene Hexafluropropene Hexachlorobutadinene T richloroethylene Chloroform Carbon tetrachloride Maleic acid Citrinin Metals Mercury Uranyl nitrate Cadmium Chromium... 

As this category of penicillins was used for treatment, S. aureus and S. epidermidis became resistant to them through the production of altered penicillin-binding proteins. These strains of staphylococci are called methicillin resistant, which denotes resistance not only to all penicillinase-resistant penicillins but to all penicillin drugs. Methicillin-resistant staphylococci have become a major problem in treatment because they are also resistant to the cephalosporins, aminoglycosides, and macrolides. For this reason vancomycin, a more toxic antibiotic, is the drug of choice for these organisms. 

It is extremely important that fluoroquinolones have a specific mechanism of action, different from antibiotics and other groups of antibacterials (cephalosporins, aminoglycosides, etc.), which allows one to apply fluoroquinolones for treatment of infectious diseases caused by strains resistant to many other classes of antibacterials drugs. 

Administration of the aminoglycosides with the cephalosporins may increase the risks of nephrotoxicity. When the aminoglycosides are administered with loop diuretics there is an increased risk of ototoxicity (irreversible hearing loss). There is an increased risk of neuromuscular blockage (paralysis of the respiratory muscles) if the aminoglycosides are given shortly after general anesthetics (neuromuscular junction blockers). 

The effects of warfarin may increase when administered with acetaminophen, NSAIDs, beta blockers, disulfiram, isoniazid, chloral hydrate, loop diuretics, aminoglycosides, cimetidine, tetracyclines, and cephalosporins. Oral contraceptives, ascorbic acid, barbiturates, diuretics, and vitamin K decrease the effects of warfarin. Because die effects of warfarin are influenced by many drugp, die patient must notify die nurse or die primary healdi care provider when taking a new drug or discontinuing... 

When used for intraabdominal infection, aminoglycosides should be combined with agents that are effective against the majority of B. fragilis. Clindamycin or metronidazole is the agent of first choice, but others, such as antianaerobic cephalosporins (e.g., cefoxitin, cefotetan, or ceftizoxime), piperacillin, mezlocillin, and combinations of extended-spectrum penicillins... 

Cirrhosis Peritoneal Cefotaxime Regimen based on organism isolated 1. Add clindamycin or metronidazole if anaerobes are suspected 2. Other third-generation cephalosporins, extended-spectrum penicillins, aztreonam, and imipenem as alternatives 3. Aminoglycoside with antipseudomonal penicillin... 

Perforated peptic ulcer First-generation cephalosporins 1. Antianaerobic cephalosporins3 2. Possibly add aminoglycoside if patient condition is poor 3. Aminoglycoside with clindamycin or metronidazole add ampicillin if patient is immunocompromised or if biliary tract origin of infection... 

Spleen Aminoglycoside plus penicillinase-resistant penicillin Alternatives for penicillinase-resistant penicillin are first-generation cephalosporins or vancomycin... 

These agents are generally effective for susceptible bacteria. The extended-spectrum penicillins are more active against P. aeruginosa and enterococci and are preferred over cephalosporins. They are very useful in renally impaired patients or when an aminoglycoside is to be avoided. 

Urinary tract Third-generation cephalosporin (ceftriaxone) OR Fluoroquinolone (levofloxacin or ciprofloxacin) Antipseudomonal penicillin OR Antipseudomonal cephalosporin OR Antipseudomonal carbapenem plus aminoglycoside... 

Treatment for septic patients with hospital-acquired, ventilator-acquired, and health care-associated pneumonia is dependent on risk factors for multi-drug resistant (MDR) organisms (Fig. 79-2). Recommended treatment for patients with no MDR risk factors are third-generation cephalosporins, fluoroquinolones, ampicillin-sulbactam, or ertapenem (see Table 79-3).35 Recommended treatment for patients with MDR risk factors are P-lactam/p-lactamase inhibitors (piperacillin-tazobactam), antipseudomonal cephalosporin, or carbapenem, plus an aminoglycoside, plus vancomycin or linezolid (see Table 79-3).35 If an aminoglycoside is undesirable, a antipseudomonal fluoroquinolone may be utilized with a P-lactam/p-lactamase inhibitor. 

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