fluoroquinolone
[floor″o-kwin´o-lōn] Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
fluor·o·quin·o·lone
(flūr'ō-kwin'ō-lōn), A class of antibiotics with a broad spectrum of antimicrobial activity, well absorbed orally, with good tissue penetration and relatively long duration of action.
Fluoroquinolone antibiotics inhibit bacterial DNA gyrase, which is necessary for the replication of DNA as well as of plasmids involved in certain types of bacterial resistance. Nalidixic acid, a nonfluorinated quinolone, has been used since the 1960s to treat urinary tract infections, but its value is limited by poor systemic distribution, lack of action against gram-positive organisms, and rapid development of bacterial resistance. In contrast, the fluoroquinolones, which contain a fluorine atom, quickly achieve therapeutic concentration in plasma, tissues, and urine after oral administration and are active against some gram-positive bacteria. Although the fluorine atom also retards the development of bacterial resistance, widespread use of fluoroquinolones during the 1990s led to a significant and continuing rise in resistance among aerobic gram-negative bacilli. Second- and third-generation fluoroquinolones are useful in community-acquired pneumonia, acute exacerbation of chronic bronchitis, bacterial rhinosinusitis, and urinary tract infections. Several of these agents are approved for single-dose oral treatment of uncomplicated gonorrhea. They are generally inactive against anaerobes and beta-hemolytic streptococci. Trovafloxacin, the only fourth-generation fluoroquinolone currently available, has the broadest spectrum, including anaerobic organisms that cause intraabdominal and pelvic infections. Its usefulness is limited, however, by a high risk of hepatotoxicity. The fluoroquinolones are generally well tolerated. The most frequent side effects are nausea, abdominal distress, dizziness, and insomnia. Elimination is primarily renal, and dosage must be adjusted for patients with renal failure. The drugs accumulate in articular cartilage and can can cause severe damage during rapid growth of that tissue; hence, they are contraindicated in patients younger than 18. Blood dyscrasias and renal toxicity have occasionally been observed. Use during strenuous exercise may be hazardous to joints and can cause tendon rupture. These drugs can interfere with the hepatic biotransformation of theophylline and warfarin.
Farlex Partner Medical Dictionary © Farlex 2012
fluoroquinolone
(flo͝or′ə-kwĭn′ə-lōn′, flôr′-)n. Any of a group of broad-spectrum antibiotics that are fluorinated quinolones, the first of which was nalidixic acid.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
fluoroquinolone
Antibiotics A quinolone with an added flourine on the parent quinolone structure. See Quinolone. McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.
fluor·o·quin·o·lone
(flōr'ō-kwin'ō-lōn) A class of antibiotics with a broad spectrum of antimicrobial activity, well absorbed orally, with good tissue penetration and relatively long duration of action.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
antibiotic
1. Pertaining to the ability to destroy or inhibit other living organisms.
2. A substance derived from a mould or bacterium, or produced synthetically, that destroys
(bactericidal) or inhibits the growth
(bacteriostatic) of other microorganisms and is thus used to treat infections. Some substances have a narrow spectrum of activity whereas others act against a wide range of both gram-positive and gram-negative organisms (
broad-spectrum antibiotics). Antibiotics can be classified into several groups according to their mode of action on or within bacteria: (1) Drugs inhibiting bacterial cell wall synthesis, such as bacitracin, vancomycin and the β-lactams based agents (e.g. penicillin, cephalosporins (e.g. ceftazidime, ceftriaxone, cefuroxime). (2) Drugs affecting the bacterial cytoplasmic membrane, such as polymyxin B sulfate and gramicidin. (3) Drugs inhibiting bacterial protein synthesis, such as aminoglycosides (e.g. amikacin sulfate, framycetin sulfate, gentamicin, neomycin sulfate and tobramycin), tetracyclines, macrolides (e.g. erythromycin and azithromycin) and chloramphenicol. (4) Drugs inhibiting the intermediate metabolism of bacteria, such as sulfonamides (e.g. sulfacetamide sodium) and trimethoprim. (5) Drugs inhibiting bacterial DNA synthesis, such as nalixidic acid and fluoroquinolones (e.g. ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin and ofloxacin). (6) Other antibiotics such as fusidic acid, the diamidines, such as propamidine isethionate and dibrompropamidine.
Syn. antibacterial.
See antiinflammatory drug;
fusidic acid.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann