Quinolones Flashcards
What is this?
quinolone
What is this?
cinnolone
What is this?
1,8-Napthyridone
What is this?
pyridopyrimidone
Which drugs are first gen quinolones?
- oxolinic acid
- nalidixic acid
discontinued
What are the characteristics of first generation quinolones?
oxolinic acid, nalidixic acid
- narrow gram-negative spectrum
- didn’t achieve useful concentrations
- only useful for UTI
Which drug is a second gen quinolone?
ciprofloxacin
What are the characteristics of the second generation quinolones?
ciprofloxacin
- fluorine substituent at C6
- heterocyclic ring at C7
- broader spectrum
Which drugs are third and fourth gen quinolones?
- levofloxacin
- moxifloxacin
What are the characteristics of the third and fourth generation quinolones?
levofloxacin, moxifloxacin
- improved activity against gram-positive
- none of them are as potent as cipro against gram-negative
What is the mechanism of action of quinolones?
- Bind to the cleavage complex that forms during DNA replication
- This stabilizes the complex and inhibits the religation reaction
- This blocks the progression of the replication fork and the double-strand breaks eventually lead to apoptosis
topo II
What are the therapeutic uses for the quinolones?
- UTI
- prostatitis
- STDs
- diabetic foot infections
What are the resistance mechanisms against quinolones?
- decreased cellular permeability
- efflux pumps
- mutation of the target enzymes
- incidence of resistance is low relative to other abx agents
- point mutations can occur at A subunit of DNA gyrase for B subunit of DNA gyrase
- mutations at both sites give rise to more highly resistant strains
Describe the absorption of quinolones:
The quinolones are all readily absorbed orally and have a high degree of bioavailability.
How well are quinolones distributed?
Quinolones are widely distributed
