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Nalidixic Acid
- Original quinolone
- Narrow spectrum of activity
- Historic interest only
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Drugs of Importance
- Ciprofloxacin
- Levofloxacin
- Moxifloxacin
- Gemifloxacin (Oral only)
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Mechanism of Action
- Bactericidal agent
- Targets enzymes important for DNA replication (DNA Gryase and Topoisomerase IV)
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Mechanisms of Resistance
- Efflux Pumps
- Cell membrane permeability (ex. Pseudomonas)
- DNA mutations resulting in decreases affinity for DNA Gyrase and Topoisomerase IV
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Pharmacokinetics
- Bioavailability: 80-90%
- Distribution: Wide volume of distribution into most body sites.
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Spectrum of Activity
- PEcK (with some exceptions)
- Enterobacter
- Variable S. Aureus
- S. pneumoniae (with one exception)
- S. pyogenes
- Leginella
- Atypical bacteria
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Ciprofloxacin
- Metabolism: Partially metabolized in liver
- Elimination: Parent and metabolites through urine
- Doesn't cover S. aureus and S. pneumoniae
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Levofloxacin
- Metabolism: No significant metabolism
- Elimination: Through urine
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Moxifloxacin
- Metabolism: Significant hepatic metabolism (more than ciprofloxacin) Can't be used in UTIs
- Elimination: Parent (minor) and metabolites (major) through feces and urine.
- Effective against B. fragilis
- Not effective against Pseudomonas
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Gemifloxacin
- Oral only
- Metabolism: Very limited hepatic metabolism
- Elimination: Parent (major) and metabolities (minor) through urine
Not effective against Pseudomonas
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Therapeutic Uses
- Respiratory Tract Infections: CAP, HAP/VAP/HCAP
- GU Infections: Cystitis/pyelonephritis (not moxi.)
- STDs
- Bacterial Gastroenteritis
- Osteomyelitis
- SSTI (newer agents)
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Adverse Reactions
- N/V/D and Abdominal discomfort
- H/A, Dizziness, Insomnia, Alteration in mood (More so in the elderly)
- Seizures (Rare)
- Cardiac Toxicity - Boxed Warning
- Tendon toxicity
- Cartilage Malformation
- Glycemic Abnormalities
- Photosensitivity
- Rash
- Hepatic toxicity
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Drug Interactions
- Antacids - reduce absorption
- Sucralfate
- Theophylline and Caffeine (inc conc. by cipro.)
- Warfarin
- Drugs known to prolong QT interval
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