The Way Forward: High-Dose, Short-Course Levofloxacin Leads the Field

29 March, 2018

Question 22

How do the resistance rates to levofloxacin compare to those reported for other antimicrobial agents in regard to common respiratory tract pathogens?

Susceptibility of S. pneumoniae has remained at over 99% while, in contrast, the susceptibility rate to ciprofloxacin is only 82.0%, cefuroxime 78.0%, trimethoprim-sulfamethoxazole 72.2% and penicillin 64.0% (Table 8).

Table 8. TRUST 11 (2007) national susceptibility of Streptococcus pneumoniae (n = 3,720)

Antimicrobial agent

% S

% I

% R

Levofloxacin

99.2

0.1

0.7

Moxifloxacin

99.3

0.5

0.2

Ceftriaxone (non-meningitis)

95.3

3.3

1.4

Amoxicillin/clavulanic acid (non-meningitis)

88.2

2.7

9.1

Ciprofloxacin ^a

82.0

15.8

2.2

Tetracycline

80.8

0.4

18.8

Cefuroxime (oral)

78.0

3.5

18.5

Trimethoprim-sulfamethoxazole

72.2

7.7

20.1

Azithromycin

67.4

0.3

32.3

Penicillin (oral)

64.0

22.7

13.3

In vitro activity does not necessarily correlate with clinical results.

^a	Ciprofloxacin FDA breakpoints used: susceptible < 1 mg/ml; intermediate 2 mg/ml; resistant > 4 mg/ml. Breakpoints (S/I/R) for other antimicrobials are CLSI.

Abbreviations:

%S = percent susceptible, %I = percent intermediate-resistant, %R = percent resistant, CLSI = Clinical and Laboratory Standards Institute.

Adapted from reference (69).