Quinolone Antimicrobial Agents Flashcards
What do first generation quinolones have limited activity against
gram (+) bacteria
What are first generation quinolones only useful for
treatment of lower urinary tract infections
Describe the activity of second generation quinolones
broader spectrum of bactericidal activity and are more potent
Most potent fluoroquinolone
Ciprofloxacin
What do second generation quinolones have activity against
extended activity against gram (+) organisms and mycoplasma
What do 3rd and 4th generation quinolones have improved activity against
gram (+) organisms, particularly Streptococcus pneumoniae
Moxifloxacin is considered?
a drug of last resort because of its severe side effects
What do gyrases and topoisomerases do?
untangle DNA by cutting one or two strands, and then allowing strand passage through the break or allowing the DNA to twist
How do different topoisomerases cleave DNA
so that either the 3’-hydroxyl or the 5’-hydroxyl of the DNA can become enzyme-linked
The topoisomerase-catalyzed reaction is?
reversible and usually equilibrium favors the uncleaved DNA, so cleavage complexes are present in very small amounts
How do bacterial/mammalian gyrases and topoisomerases cleave DNA
cleaves both opposing strands with a four-base stagger
What step is blocked by quinolones
DNA religation
Most common use of quinolones
urinary tract infections
Which quinolones are effective for urinary tract infections
Norfloxacin, ciprofloxacin, ofloxacin, and nalidixic acid
Which quinolones are effective for prostatitis?
Norfloxacin, ciprofloxcin, and ofloxacin
Which STDs are quinolones effective against
Neisseria gonorrhoeae, Chlamydia trachomatic, and Haemophilus ducreyi
Which quinolones do you use for Chlamydia trachomatis
ofloxacin or sparfloxacin
Which quinolone do you use for Haemophilus ducreyi
ciprofloxacin
First line treatment of Neisseria gonorrhoeae
ceftriaxone (a cephalosporin)
Effective quinolone treatments for shigellosis
Norfloxacin, ciprofloxacin, and ofloxacin
Many of the newer fluoroquinolones, including moxifloxacin have excellent activity versus?
Streptococcus pneumoniae
Respiratory tract exacerbations in cystic fibrosis patients are responded to?
fluoroquinolone therapy
Sole therapy in 50% of diabetic foot infections
ciprofloxacin
Treatment of bone, joint, and soft tissue infections with quinolones
fluoroquinolones (except norfloxacin)
Which quinolones have useful activity against intracellular bacteria
norfloxacin and ciprofoxacin
Clearance of fluoroquinolones?
renal and hepatic clearance (except oxafloxacin)
Why should quinolones not be administered with foods and drugs that contain heavy metals
quinolones form insoluble chelates with heavy metals
CNS side effects of quinolones
headache and dizziness
rare hallucinations, delirium and seizures
associated with peripheral neuropathies
Why are quinolones not recommended for patients under the age of 18
fluoroquinolones may damage growing cartilage and cause arthropathy
Adverse effects with specific agents:
- photosensitivity with lomefloxacin
2. hyperglycemia and hypoglycemia in diabetic patients with gatifloxacin
