Quinolone Antibiotics: Still Reliable Against Gram-negative Species?

Advances in environmental sanitation, immunizations, antimicrobial therapy, and medical research have greatly reduced the impact of infectious diseases (IDs) on our communities. Nonetheless, infections and the cost of treating them remain a burden to the health care system.

In primary care practice, we may spend more time making referrals for suspected ID than actually treating infected patients. Here, as a brush up, is the seventh in our series of 10 practical ID pearls.

7. How reliable are quinolones for empiric therapy against gram-negative infections?

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Then click here for the answer and discussion.

Answer: Quinolones are no longer highly reliable as empiric therapy against gram-negative infections.

A recent study revealed a 5-fold increase in Escherichia coli resistance to quinolones-from 3% in 2000 to 17% in 2010.¹ The data were obtained from a surveillance network database that included information from 200 institutions in the US and included more than 12 million isolates of E coli. Other studies have reported Pseudomonas resistance to quinolones of greater than 50%.² Quinolones can be used with confidence when a positive culture for gram-negative species with proven sensitivity to quinolones is demonstrated.

References
1. Sanchez GV. In vitro antimicrobial resistance of urinary escherichia coli isolates among U.S. outpatients from 2000 to 2010. Antimicrob Agents Chemother. 2012;56:2181-2183. (Full text)

2. Hsu D, Okamoto M, Murthy R,  Wong-Beringer A. Fluoroquinolone-resistant pseudomonasaeruginosa: Risk factors for acquisition and impact on outcomes. J Antimicrob Chemother. 2005;55:535-541. (Full text)

See below for all previous ID Pearls:

Practical ID Pearl #1

Pracitcal ID Pearl #2

Pracitcal ID Pearl #3

Pracitcal ID Pearl #4

Pracitcal ID Pearl #5

Pracitcal ID Pearl #6