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Fluoroquinolones /Quinolone; Types, Side Effects, Interactions

Fluoroquinolones /quinolone antibiotic is any member of a large group of broad-spectrum bactericides that share a bicyclic core structure related to the compound 4-quinolone. They are used in human and veterinary medicine to treat bacterial infections, as well as in animal husbandry. Nearly all quinolone antibiotics in modern use are fluoroquinolones, which contain a fluorine atom in their chemical structure and are effective against both Gram-negative and Gram-positive bacteria. One example is ciprofloxacin, one of the most widely used antibiotics worldwide.

Types of Fluoroquinolones /Quinolone

First generation

flumequine
oxolinic acid
rosoxacin

Structurally related first-generation drugs, but formally not 4-quinolones, include cinoxacin, nalidixic acid, and piromidic acid, pipemidic acid

Second generation

The second-generation class is sometimes subdivided into “Class 1” and “Class 2”.

ciprofloxacin
fleroxacin
lomefloxacin
nadifloxacin
norfloxacin
ofloxacin
pefloxacin
rufloxacin

A structurally related second-generation drug, but formally not a 4-quinolone, is enoxacin

Third generation

Unlike the first and second generations, the third generation is active against streptococci.

balofloxacin
grepafloxacin
levofloxacin
pazufloxacin
sparfloxacin
temafloxacin

A structurally related third-generation drug, but formally not a 4-quinolone, is tosufloxacin

Fourth generation

Fourth-generation fluoroquinolones act at DNA gyrase and topoisomerase IV. This dual action slows development of resistance.

clinafloxacin
gatifloxacin
moxifloxacin
sitafloxacin
prulifloxacin
besifloxacin

Two structurally related third generation drugs, but formally not 4-quinolones, are gemifloxacin and trovafloxacin

Types of Fluoroquinolones /Quinolone

1st generation

Cinoxacin
Flumequine
Nalidixic acid
Oxolinic acid
Pipemidic acid
Piromidic acid
Rosoxacin

Fluoro-
quinolones

2nd generation	Ciprofloxacin Ofloxacin Enoxacin Fleroxacin Lomefloxacin Nadifloxacin Norfloxacin Pefloxacin Rufloxacin
3rd generation	Levofloxacin Balofloxacin Grepafloxacin Pazufloxacin Sparfloxacin Temafloxacin Tosufloxacin
4th generation	Besifloxacin Delafloxacin Gatifloxacin Finafloxacin Gemifloxacin Moxifloxacin Clinafloxacin Garenoxacin Prulifloxacin Sitafloxacin Trovafloxacin/Alatrofloxacin
Vet.	Danofloxacin Difloxacin Enrofloxacin Ibafloxacin Marbofloxacin Orbifloxacin Pradofloxacin Sarafloxacin

Mechanism of Action of Fluoroquinolones /Quinolone

The bactericidal action of ciprofloxacin results from inhibition of the enzymes topoisomerase II (DNA gyrase) and topoisomerase IV, which are required for bacterial DNA replication, transcription, repair, strand supercoiling repair, and recombination.

The mechanism by which ciprofloxacin’s inhibition of DNA gyrase or topoisomerase IV results in death in susceptible organisms has not been fully determined. Unlike beta-lactam anti-infectives, which are most active against susceptible bacteria when they are in the logarithmic phase of growth, studies using Escherichia coli and Pseudomonas aeruginosa indicate that ciprofloxacin can be bactericidal during both logarithmic and stationary phases of growth; this effect does not appear to occur with gram-positive bacteria (e.g., Staphylococcus aureus). In vitro studies indicate that ciprofloxacin concentrations that approximate the minimum inhibitory concentration (MIC) of the drug induce filamentation in susceptible organisms; high concentrations of the drug result in enlarged or elongated cells that may not be extensively filamented. Although the bactericidal effect of some fluoroquinolones (e.g., norfloxacin) evidently requires competent RNA and protein synthesis in the bacterial cell, and concurrent use of anti-infectives that affect protein synthesis (e.g., chloramphenicol, tetracyclines) or RNA synthesis (e.g., rifampin) inhibit the in vitro bactericidal activity of these drugs, the bactericidal effect of ciprofloxacin is only partially reduced in the presence of these anti-infectives. This suggests that ciprofloxacin has an additional mechanism of action that is independent of RNA and protein synthesis.

Indications of Fluoroquinolones /Quinolone

Upper/Lower respiratory tract infection (respiratory, skin, soft tissue, UTI, ENT)
Infectious diarrheas caused by E. coli, Campylobacter jejuni, and Shigella bacteria.
Skin infections
Lung or airway Infections, for example, TB (tuberculosis), pneumonic and septicemic plague due to Yersinia pestis (Y. pestis), lower respiratory tract infections, and chronic bronchitis)
Bone and Joint Infections
Anthrax patients with fever and low white blood cell counts, and intra-abdominal infections.
Acute bacterial otitis media
Skin and skin structure infections
Urinary tract infections
Uncomplicated gonorrhea
Pelvic inflammatory disease
Bacterial septicemia
Intra-abdominal infections
Pelvic Inflammatory Disease
Meningitis
Osteomyelitis
Pelvic Inflammatory Disease
Surgical prophylaxis
Community-acquired pneumonia
Acute otitis media
Intra-abdominal infections
Complicated urinary tract infections (including pyelonephritis)
Infections of bones and joints
Complicated skin and soft tissue infections
Gonorrhea
Syphilis
Bacterial Endocarditis.
Meningococcal Meningitis Prophylaxis
Salmonella Enteric Fever
Salmonella Gastroenteritis
Community-acquired pneumonia
Hospital-acquired pneumonia
Acute otitis media
Intra-abdominal infections
Complicated urinary tract infections (including pyelonephritis)
Infections of bones and joints
Complicated skin and soft tissue infections
For treatment of acute exacerbations of chronic obstructive pulmonary disease in adults
For treatment of disseminated Lyme borreliosis (early (stage II) and late (stage III)) in adults and children including neonates from 15 days of age.
|For Pre-operative prophylaxis of surgical site infections