Table 3.
Susceptibility of respiratory tract isolates (1998 to 2000) to antimicrobial agents at PK/PD breakpoints89, 90
| Agent | Percentage of isolates susceptible at PK/PD breakpoint |
||||||
|---|---|---|---|---|---|---|---|
| Susceptibility breakpoint (μg/mL) (PK/PD) | S pneu-moniae (all) (n = 2901) | Penicillin-susceptible S pneu-moniae (n = 1845) | Penicillin-intermediate S pneumoniae (n = 382) | Penicillin-resistant S pneumoniae (n = 674) | H influ-enzae (n = 1919) | M catar-rhalis (n = 204) | |
| Amoxicillin | ≤2 | 91.6 | 100 | 100 | 63.6 | 70.2 | 7.3 |
| Amoxicillin HD∗ | ≤4 | 95.2 | 100 | 100 | 79.4 | 70.2 | 7.3 |
| Amox/Clav† | ≤2 | 92.1 | 100 | 99.7 | 66.3 | 98.3 | 100 |
| Amox/Clav HD/extended release∗, † | ≤4 | 95.2 | 100 | 100 | 79.4 | 99.8 | 100 |
| Cefaclor | ≤0.5 | 19.7 | 30.3 | 2.9 | 0.1 | 3.7 | 8.7 |
| Cefuroxime axetil | ≤1 | 72.6 | 99.9 | 68.8 | 0.0 | 82.8 | 50.5 |
| Cefixime | ≤1 | 66.3 | 96.7 | 35.3 | 0.4 | >99.9 | 100 |
| Ceftriaxone | ≤1 | 96.3 | 100 | 99.5 | 84.6 | >99.9 | 93.6 |
| Cefprozil | ≤1 | 71.8 | 99.7 | 63.1 | 0.4 | 23.2 | 9.2 |
| Cefpodoxime‡ | ≤0.5 | 75.4 | 99.7 | 67.4 | 0.7 | 100 | 85.0 |
| Cefdinir | ≤0.25 | 68.8 | 98.4 | 49.2 | 0.5 | 78.2 | 77.6 |
| Loracarbef | ≤0.5 | 7.6 | 10.3 | 6.5 | 0 | 9.6 | |
| Erythromycin | ≤0.25 | 72.0 | 92.6 | 49.7 | 28.0 | 0.0 | 100 |
| Clarithromycin | ≤0.25 | 72.3 | 92.8 | 51.0 | 28.2 | 0.0 | 100 |
| Azithromycin | ≤0.12 | 71.0 | 91.8 | 48.4 | 27.2 | 2.3 | 100 |
| Clindamycin | ≤0.25 | 90.6 | 97.9 | 81.4 | 75.8 | 0 | 0 |
| Ciprofloxacin | ≤1 | § | § | § | § | 100 | 100 |
| Levofloxacin | ≤2 | 99.1 | 99.0 | 99.7 | 99.1 | 100 | 100 |
| Gatifloxacin | ≤1 | 99.1 | 99.0 | 99.7 | 99.1 | 100 | 100 |
| Moxifloxacin | ≤1 | 99.2 | 99.0 | 100 | 99.3 | 100 | 100 |
| Doxycycline | ≤0.25 | 80.4 | 95.2 | 65.2 | 48.7 | 25.1 | 96.3 |
| TMP/SMX¶ | ≤0.5 | 63.7 | 86.4 | 46.1 | 11.3 | 78.1 | 19.3 |
The activity of telithromycin against S pneumoniae, H influenzae, and M catarrhalis depends on its PK/PD breakpoint, which is uncertain at this time. The activity of telithromycin is assumed to be similar to that of macrolides/azalides until further information becomes available.
Amox/clav, amoxicillin/clavulanate; NA, not applicable; PD, pharmacodynamic; PK, pharmacokinetic; TMP/SMX, trimethoprim/sulfamethoxazole. All values are based on PK/PD breakpoints, except for S pneumoniae, in which values are shown as PK/PD and new (Jan 2000) NCCLS breakpoints and for clindamycin and TMP/SMX, in which NCCLS breakpoints are used. Data are adapted from reference 88.
High-dose amoxicillin or amoxicillin-clavulanate as defined in text.
Shown as amoxicillin component.
Susceptibility data for cefpodoxime were obtained from the SENTRY database.90
The MICs of ciprofloxacin against some isolates of S pneumoniae are above the PK/PD breakpoint; therefore, ciprofloxacin does not reliably cover this organism.
Shown as TMP component.