Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Quinolones are broad-spectrum antibiotics active primarily against aerobic gram-negative organisms. All quinolones have activity against oral anaerobes, but only trovafloxacin provides coverage against Bacteroides fragilis, the primary anaerobe of the abdomen/pelvis. In addition, quinolones are very active against atypical pulmonary pathogens, e.g., Legionella, but trovafloxacin is the least active against Chlamydia. As with other antibiotics, the selection of quinolones depends not simply on the degree of microbiologic activity but also on safety profile and cost. Ciprofloxacin and trovafloxacin are associated with central nervous system side effects. Photosensitivity reactions may occur with sparfloxacin. Trovafloxacin is associated with more adverse reactions than any other quinolone, and its gastrointestinal side effects are most frequent among the quinolones. Resistance potential is highest with ciprofloxacin and lowest with levofloxacin. Sparfloxacin and grepafloxacin are available only as oral formulations. Among the parenteral quinolones, ciprofloxacin and trovafloxacin are the most expensive, levofloxacin, the least expensive. Levofloxacin is preferred for general use alone or in combination because it has virtually no side effects, induces no resistance, and is the least expensive and most versatile quinolone currently available.
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PMID:Quinolones: clinical use and formulary considerations. 1034 49

The treatment of respiratory tract infection is the most common reason for antibiotic prescribing. However, therapeutic options are diminishing as antibiotic resistance to penicillins and macrolides in key respiratory pathogens is increasing. As resistance increases, there are parallel rises in the number of treatment failures and the total cost of infection management. New generation broad-spectrum fluoroquinolones, such as grepafloxacin, have recently been recommended as a first-line treatment option in guidelines for lower respiratory tract infection. Grepafloxacin is an oral fluoroquinolone, with a microbiological and clinical profile that is particularly suited to the treatment of community-acquired respiratory infections. In vitro, it is rapidly bactericidal, and compared with earlier quinolones, its broad spectrum activity encompasses all important respiratory pathogens; Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila, including strains which are resistant to penicillin, other beta-lactam antibiotics and macrolides. In addition, grepafloxacin achieves high lung concentrations, and its long half-life (up to 15 h) enables once daily dosing. Overall, grepafloxacin combines the positive properties of the beta-lactam antibiotics against conventional Gram-positive and Gram-negative respiratory pathogens, with the activity of the macrolides against atypical pathogens. In patients with bacteriologically documented infections, clinical studies in community-acquired pneumonia have shown that treatment for 7-10 days once daily (o.d.) with approximately 600 mg is equivalent to that with either twice daily (b.i.d.) clarithromycin 250 mg, or three times daily (t.i.d.) cefaclor 500 mg, and superior to that with t.i.d. amoxycillin 500 mg. In these studies, grepafloxacin proved effective in the treatment of both typical and atypical pneumonia. In acute bacterial exacerbations of chronic bronchitis (ABECB), 7-10 days treatment with o.d. grepafloxacin 400 mg or 600 mg has been shown to be equivalent to that with either t.i.d. amoxycillin 500 mg, or b.i.d. ciprofloxacin 500 mg. In patients with a documented bacterial pathogen, microbiological success with both grepafloxacin dosage regimens was superior to amoxycillin 500 mg t.i.d. In addition, short course treatment of ABECB with 400 mg of grepafloxacin given o.d. for five days has been shown to be as effective, clinically and microbiologically as a ten-day course of the same dose. The safety profile of grepafloxacin has been well-characterised from data from over 12,000 patients treated in Phase II/III and post-marketing studies, and over 400,000 patients treated worldwide in routine clinical practice. The most commonly reported adverse events are gastrointestinal, mainly nausea and unpleasant taste. The potential for photosensitivity and central nervous system effects is low, and there have been no reports of convulsions. No unique or unexpected.
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PMID:Grepafloxacin: an overview of antibacterial activity, pharmacokinetics, clinical efficacy and safety. 1599 94