TABLE 3.
Log burden of H. influenzae in rat lung at day 7 of therapy with clarithromycin or azithromycin
| Drug/dosagea | H. influenzae 43095b (% respondersc) | H. influenzae 1435b (% respondersc) | H. influenzae 3556b (% respondersc) | H. influenzae 3643b (% respondersc) | H. influenzae 3558b (% respondersc) |
|---|---|---|---|---|---|
| Clarithromycin | MIC = 4 | MIC = 8 | MIC = 16 | MIC = 32 | MIC = 16 |
| 150 mg/kg | 0.54 ± 0.36d (100%) | 0.38 ± 0.38d (100%) | NDd,e (100%) | NDd,e (100%) | NDd,e (100%) |
| 100 mg/kg | 1.20 ± 0.50d (100%) | 0.57 ± 0.38d (100%) | 0.57 ± 1.20d (100%) | NDd,e (100%) | 1.00 ± 0.00d (100%) |
| Azithromycin | MIC = 2 | MIC = 2 | MIC = 4 | MIC = 4 | MIC = 4 |
| 50/25 mg/kg | 0.40 ± 0.40d (100) | 0.59 ± 0.59d (100%) | NDd,e (100%) | NDd,e (100%) | NDd,e (100%) |
| 25/12.5 mg/kg | 0.96 ± 0.53d (100%) | 6.61 ± 0.53 (20%) | 4.53 ± 2.78 (40%) | NDd,e (100%) | 0.60 ± 0.40d (100%) |
| Untreated | 6.58 ± 0.20 | 7.63 ± 0.26 | 6.73 ± 0.32 | 6.57 ± 0.19 | 7.23 ± 0.15 |
a
Clarithromycin dosage, b.i.d. on days 0 to 6; azithromycin dosage QD on days 1 to 6; 2× strength dosage on day 0.
b
Mean log count ± standard deviation.
c
Percent responders, percentage of rats with >2-log reduction in H. influenzae burden.
d
Significantly lower than untreated controls (P < 0.01).
e
ND, none detected.