Gentamicin spectrum

Gentamicin Micromonospora purpurea Broad spectrum Protein synthesis... 

Erythromycin is considered the optimal drug for treatment of Campylobacter infections. The rate of resistance of Campylobacter to erythromycin remains low. Other advantages of this drug include ease of administration, low cost, lack of major toxicity, and narrow spectrum of activity.14 The recommended dosage for adults is 250 mg orally four times daily or 500 mg orally twice daily for 5 to 7 days. For very ill patients, treatment with gentamicin, imipenem, cefotaxime, or chloramphenicol is indicated, but susceptibility tests should be performed. 

A 43-year-old male in the surgical ICU after exploratory laparotomy following a motor vehicle accident develops fever that is unresponsive to broad-spectrum antibacterial therapy (piperacillin-tazobactam 3.75 g every 6 hours, gentamicin 120 mg every 8 hours, and vancomycin 1 g every 12 hours). The patient has a central venous catheter and a Foley catheter. Blood cultures are negative at the time, but the patient has yeast growing in the sputum and urine. Laboratory studies reveal a white blood cell count of 11,300 cells/mm3 (11.3 x 109/L). 

Blepharitis is a topical inflammation of the eyelid margins that should be treated using topical antibacterial agents. Gentamicin eye ointment is preferred to the fusidic acid drops since the ointment is a better formulation to be used where the condition involves the eyelid margins. Chloramphenicol eye drops is the third option since it is an antibiotic with a wider spectrum of activity. A combination of corticosteroid and antibiotic is not recommended because of the side-effects associated with the steroid. The use of oral tablets is not usually recommended since blepharitis can easily be managed with topical drops. The use of dexamethasone eye drops, monotherapy steroid, could clear the inflammation but mask persistence of infection. 

Gentamicin has a broad spectrum of biological action, and is highly active with respect to strains of staphylococci that are resistant to penicilhns and other antibiotics, many Gramnegative microorganisms blue-pus bacillus, rabbit fever, enterobacter, salmonella, shigella, and proteus. 

Bertram G, Bell HA, Ritchie DW, Fullerton G, Stansfield I (2000) Terminating errkaryote translation domain 1 of release factor eRFl functions in stop codon recognition. RNA 6 1236-1247 Bidou L, Hatin I, Perez N, Allamand V, Panthier JJ, Rousset JP (2004) Premature stop codons involved in muscular dystrophies show a broad spectrum of readthrough efficiencies in response to gentamicin treatment. Gene Ther 11 619-627... 

This aminoglycoside (Figure 45-2) has an antibacterial spectrum similar to that of gentamicin. Although there is some cross-resistance between gentamicin and tobramycin, it is unpredictable in individual strains. Separate laboratory susceptibility tests are therefore necessary. 

Of the other broad-spectrum antibiotics commonly used in hospitals, gentamicin does not penetrate the CNS to achieve therapeutically useful concentrations and ciprofloxacin is not reliable against S. pneumoniae. Of the car-bapenems, meropenem achieves better CNS penetration than imipenem. Vancomycin has poor CNS penetration but is prescribed routinely in countries with penicillin-resistant S. pneumoniae, often with rifampicin which achieves CSF concentrations effective against S. pneumoniae but not Neisseria meningitidis or Haemophilus influenzae. 

Combination therapy is often used when dealing with infections caused by both aerobic and anaerobic bacteria [50,80]. Combination of metronidazole with either gentamicin or ciprofloxacin appeared to be effective in preventing infection of abdominal trauma [101] when combined with ciprofloxacin, metronidazole was affective as a preoperative antibiotic in colorectal surgery and appeared equal in efficacy to impipenem/cilastin for the treatment of complicated intraabdominal infections [103]. Combination therapy is not always indicated for the treatment of polymicrobial infections. New antibiotics, whose spectrum includes multiple classes of microorganisms (e.g., imipenem), may often preclude combination therapy. 

The same spectrum of toxicity (ototoxicity and nephrotoxicity) is shared by all members of the group, The more important and frequent interactions are pharmacodynamic. Streptomycin and gentamicin produce predominantly vestibular effects, whereas amikacin, kanamycin and neomycin primarily affect auditory function. All are rapidly excreted by the kidney,... 

Initial treatment of bacterial ophthalmia neonatorum should be directed by the results of conjimctival smears. Broad-spectrum antibiotics with low toxicity should be used. Topical erythromycin or tetracycline ointment can be used four to six times daily fc>r gram-positive organisms, and gentamicin or tobramycin solution four to six times daily can be started if gram-negative organisms are isolated. Trimethoprim-polymyxin B (Polytrim) has... 

Resistance to gentamicin. Gentamicin C is a broad spectrum antibiotic... 

Amikacin is derived from kanamycin and has the broadest spectrum of activity of the aminoglycosides. It is less susceptible to bacterial enzyme inactivation than the other aminoglycosides, so it is usually reserved for therapy of gentamicin-resistant bacterial infections. 

Useful spectrum includes gram-negative rods gentamicin, tobramycin, and amikadn are often used in combinations. Synergistic actions occur for infections caused by enterococci (with penicillin G or ampidllin) and P. aeruginosa (with an extended-spectrum penicillin). 

FIGURE 12.7 (See color insert following page 210.) Differential imaging analysis of a control vs. a gentamicin-treated rat kidney section. Average spectrum (cortex) and intensity distribution of m/z 12,959 on a control and a treated kidney section. (Adapted from Meistermann, H. et al., Mol. Cell. Proteomics, 5, 1876, 2006. With permission.)... 

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