Table 2. Lack of potential for fulvestrant to be involved in significant CYP3A4-mediated drug interactions. Data are geometric least squares mean (glsmean) area under the concentration-time curve from 0 to time t (AUC[0−t]) for fulvestrant (rifampicin and ketoconazole studies) and AUC for midazolam (midazolam study).
| Fulvestrant 10 mg i.v.+rifampicin 600 mg (n=6) | Fulvestrant 10 mg i.v. alone (n=6) | Treatment effecta | Lower one-sided 95% CI | Upper 95% CI |
|---|---|---|---|---|
| 208 ng h ml−1 | 211 ng h ml−1 | 0.99b | 0.65b | 1.49 |
| Fulvestrant 8 mg i.v.+ketoconazole 400 mg (n=18) | Fulvestrant 8 mg i.v. alone (n=18) | Treatment effecta | Lower 90% CI | Upper 90% CI |
| 130.6 ng h ml−1 | 143.3 ng h ml−1 | 0.91 | 0.83 | 1.00 |
| Midazolam 7.5 mg+fulvestrant 36 mg i.m. (n=7) | Midazolam 7.5 mg alone (n=7) | Treatment effecta | Lower 90% CI | Upper 90% CI |
| 135 ng h ml−1 | 123 ng h ml−1 | 1.11 | 0.83 | 1.47 |
a
Ratio of glsmeans;
b
based on data from five volunteers.