They exert their
actions by inhibiting bacterial nucleic acid synthesis through disrupting the enzymes topoisomerase IV and DNA gyrase
, and by causing breakage of bacterial chromosomes. However, bacteria have acquired resistance to quinolones, similar to other antibacterial agents, due to the overuse of these drugs.
What is the mechanism of antibacterial action of quinolones?
Quinolones bind to the
topoisomerase IV/DNA gyrase
–DNA complexes and this results in the inhibition of DNA replication. Complex forma- tion reversibly inhibits DNA synthesis and cell growth, which is probably responsible for the bacteriostatic action of quino- lones.
How do quinolones kill bacteria?
Quinolones
inhibit replication of bacterial DNA by blocking the ligase domain of bacterial DNA gyrase
(topoisomerase II); some also inhibit topoisomerase IV. These enzymes relax DNA supercoils and enable DNA replication and repair (see Fig. 51.1). The effect of quinolones is bactericidal.
Are quinolones antibacterial?
The new fluorinated quinolones differ from their predecessors in their
broad antibacterial spectrum
, including both Gram-negative and Gram-positive aerobic, and facultative anaerobic bacteria as well as many Mycobacterium spp., Chlamydia spp., Legionella spp.
Which bacterial process do quinolones inhibit?
Quinolone antimicrobials are widely used in clinical medicine and are the only current class of agents that directly inhibit
bacterial DNA synthesis
.
What antibiotics are in the quinolone family?
Fluoroquinolones are a class of antibiotics approved to treat or prevent certain bacterial infections. The fluoroquinolone antibiotics include
ciprofloxacin (Cipro)
, gemifloxacin (Factive), levofloxacin (Levaquin), moxifloxacin (Avelox), and ofloxacin (Floxin).
What antibiotics are in the tetracycline family?
| Generic name Brand name examples | tetracycline Ala-tet, Tetracap |
|---|
What are the side effects of quinolones?
The most frequent side-effects are
gastrointestinal reactions (nausea, dyspepsia, vomiting)
and CNS reactions such as dizziness, insomnia and headache. Many of the more severe CNS reactions seem to be due to metabolic interaction with theophylline, especially when enoxacin is used.
What is the difference between quinolones and fluoroquinolones?
There are several different types of antibiotics that may be used for various infections, but quinolones (also known as fluoroquinolones) are a type of infectious disease medication used primarily when there is a concern for
multidrug
resistance from other antibiotics.
What do fluoroquinolones treat?
The fluoroquinolones are indicated for treatment of several
bacterial infections
, including bacterial bronchitis, pneumonia, sinusitis, urinary tract infections, septicemia and intraabdominal infections, joint and bone infections, soft tissue and skin infections, typhoid fever, anthrax, bacterial gastroenteritis, …
Is Augmentin a quinolone antibiotic?
Augmentin is a
combination penicillin-type antibiotic
and a beta-lactamase inhibitor and Cipro is a quinolone antibiotic.
What is another name for ciprofloxacin?
Ciprofloxacin is available under the following different brand names:
Cipro, Cipro XR
, and ProQuin XR.
Is Keflex a quinolone?
Keflex is
a cephalosporin antibiotic
, and Cipro is a fluoroquinolone antibiotic. Cipro and Keflex are used to treat middle ear, skin, bone, and urinary tract infections (UTIs) caused by certain bacteria.
Which of the following is advantage of fluoroquinolones over quinolones?
Advantages of the new fluoroquinolones may include
treating bacteria that are resistant to some of the older fluoroquinolones such
as ciprofloxacin. For S pneumoniae, the primary target is fluoroquinolone dependent. The primary target for ciprofloxacin, levofloxacin, moxifloxacin and trovafloxacin is ParC (40,41).
How do fluoroquinolones affect bacteria?
A fluoroquinolone is an antibiotic that
destroys bacteria by interfering with its DNA replication
. Early generation fluoroquinolones hamper bacterial DNA synthesis during replication primarily by inhibiting DNA gyrase, one enzyme required for bacterial (but not human) DNA replication.
Is amoxicillin a quinolone?
Amoxicillin and Levaquin (levofloxacin) are both antibiotics used to treat a variety bacterial infections. Levaquin belongs to the fluoroquinolone class of antibiotics, while
amoxicillin is a penicillin type of antibiotic
.
