175. Fluoroquinolones Flashcards
Against which type of bacteria does F act? Give some example
susceptible Gram-negative, staphylococcal, and selected intracellular bacterial infections (Mycoplasma spp., Chlamydophila spp., Brucella canis, and certain mycobacteria), Streptococcus spp. and intracellular pathogens and minimal anaerobic coverage. Enterobacteriaceae (Escherichia coli, Klebsiella), Pasteurella spp., Bordetella spp., Salmonella, and Campylobacter spp. Pseudomonas aeruginosa is variably susceptible to different fluoroquinolones
What are some side effects of F?
vomiting, diarrhea, nausea, neurologic disorders, and cartilage defects in juvenile animals (is not recommended in animals <6–8 months of age, particularly in large breed dogs that are still growing). Blindness has occurred in cats given enrofloxacin (irreversible blindness in cats. Fluoroquinolone-associated retinopathy in cats appears to be dose-related and has been documented with enrofloxacin doses greater than 5 mg/kg q24h).
List some F from the second generation
enrofloxacin, marbofloxacin, ciprofloxacin, orbifloxacin
From the third
pradofloxacin
MOA of F
Inhibition of bacterial topoisomerase IV and DNA gyrase (a member of the topoisomerase family). Inhibition of these enzymes prevents normal bacterial DNA synthesis, replication, and division, resulting in bacterial cell death. Inhibition of DNA gyrase is the predominant mechanism for the killing of Gram-negative bacteria, whereas inhibition of topoisomerase IV is primarily responsible for effects on Gram-positive bacteria.
Which F is effective against multiple anaerobes?
Pradofloxacin
What is the bioavailability of F orally and parenterally?
High
Where are F metabolised and eliminated?
Fluoroquinolones undergo hepatic metabolism and are excreted in bile and/or urine, either unchanged or as metabolites. Most are eliminated by the kidney.
Lipophilic or hydrophilic?
Lipophilic
T or F: lower end of the doses may either be ineffective or more likely to induce development of resistant mutants.
T. Recommended to use the higher end. So 15-20mg/kg I suppose
Which bacteria is commonly resistant to F?
E.coli
If F reach high concentration in urine, why is it not recommended to treat uncomplicated UTIs?
Because of increasing resistance amongst common urinary tract pathogens, as well as the importance of preserving the efficacy of these drugs in treating more serious infections, such as bacterial pyelonephritis
F are good empirical choices for
bacterial prostatitis, Gram-negative aerobic pathogens that may be present in hepatobiliary infections
Why F need to be used with cautious in P with seizure disorder?
Fluoroquinolones have been shown to competitively inhibit binding of γ-aminobutyric acid, which may lower the seizure threshold in patients with idiopathic epilepsy, and thus should be avoided or used with extreme caution in patients with seizure disorders.
What can rapid IV administration cause?
Histamine release
T or F and why: The use of fluoroquinolones in patients with necrotizing fasciitis is potentially detrimental
T: Rare reports have documented that fluoroquinolones can induce activation of a latent bacteriophage within exotoxin-producing Streptococcus spp. (i.e., S. canis) isolated from a dog with necrotizing fasciitis. Bacteriophage activation can result in rapid bacterial cell lysis, release of a bacteriophage encoded streptococcal superantigen, and the potential sequelae of toxic shock syndrome
Which F is available for injectable use?
Enro
