Quinolones
From WardWiki - Foundation Doctor Helper
Quinolones are a common class of antibiotics used in primary and secondary care to treat bacterial infection by inhibition of Topoisomerase 1 and hence work on the DNA of bacteria. All except nalidixic acid, now rarely used, are fluorinated. They provide good gram negative cover; levofloxacin has better action against gram positive streptococci than the more common ciprofloxacin. They hold the unique position of being the only oral antibiotics active against pseudomonas and their oral and intravenous bioavailability is equal. This article focusses on utility to foundation doctors and is not an extensive academic discussion on these antibiotics.
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Special considerations
Quinolones are contraindicated in pregnancy due to their action against DNA. They are cautioned in patients with tendon disease (risk of tendon rupture) and epilepsy (lowering seizure threshold). They should avoided in combination with theophylline as dangerously elevated levels of theophylline can result without dose adjustments by pharmacy. Consider a switch to oral from intravenous quinolones as IV antibiotics are very expensive, consume much nursing time and are inconvenient for mobile patients. Moxifloxacin is a newer quinolone limited to use under specialist supervision in resistant chest and soft tissue infections.
Individual quinolones
Ciprofloxacin
- Oral 250-750mg BD; 500mg is the most common hospital dose
- IV 400mg BD
Levofloxacin
- Oral 250-500mg BD
- IV 500mg BD
Ofloxacin
- Oral 200-400mg OD - Commonly used for pelvic inflammatory disease
Moxifloxacin
This is strictly for specialist use only
- Oral 400mg OD
- IV 400mg OD
Links
www.bnf.org
