TABLE 1.
Mean pharmacokinetic parameters of erythromycin, azithromycin and clarithromycin following a single dose in healthy volunteers*
| Parameter | Erythromycin base (500 mg) | Erythromycin estolate** (500 mg) | Azithromycin (500 mg) | Clarithromycin (500 mg) |
|---|---|---|---|---|
| Bioavailability (%) | ∼25 | ∼25‡ | 37 | 55 |
| Cmax (μg/L) | 1.9 - 3.8 | 3.08 | 0.4 | 1.6 |
| Tmax (h) | 1 - 5 | 2.65 | 2.5 | 1.7 - 1.9 |
| AUC (μg h/L) | 5.8 - 11.2 | 20.39 | 3.39† | 4 - 4.2 |
| Protein binding (%) | 26 - 35 | 75 | 7 - 50§ | 65 - 75 |
| half-life (h) | 1.5 - 3.0 | 3.0 | 11 - 14 | 2.6 - 2.7¶ |
*
Results are reported as mean ± SD where available.
†
AUC0–72.
‡
Varies with formulation, salt form, and relation to meals.
§
May change with serum concentration.
¶
May increase with increasing doses, AUC area under the curve; Cmax maximum concentration: Tmax time to maximum concentration.
**
Erythromycin estolate data from Croteau D, Bergeron MG, LeBel M. Antimicrob Agents Chemother 1988;32:561–5.