TABLE 3.
Fenfluramine (FFA) and norfenfluramine (nFFA) potential to inhibit drug transporters—definitions and values of R
| Transporter | IC50 a (µM) | Potential to inhibit transporter | R value | ||
|---|---|---|---|---|---|
| FFA | nFFA | (R) | FFA | nFFA | |
| P‐gp | >100 | >50 | Igut/IC50 ≥ 10 | <2.2511 | NA |
| >100 | >50 | Cmax/IC50 ≥ 0.1 | NA | <0.0037 | |
| BCRP | >100 | >50 | Igut/IC50 ≥ 10 | <2.2511 | NA |
| >100 | >50 | Cmax/IC50 ≥ 0.1 | NA | <0.0037 | |
| OATP1B1 | >300 | >50 | 1+(fu,p x Iin,max)/IC50 ≥ 1.1 | <1.0012 | <1.0017 |
| OATP1B3 | >300 | >50 | 1+(fu,p x Iin,max)/IC50 ≥ 1.1 | <1.0012 | <1.0017 |
| OAT1 | >30 | >50 | Imax,u/IC50 ≥ 0.1 | <0.0054 | <0.0019 |
| OAT3 | >30 | >50 | Imax,u/IC50 ≥ 0.1 | <0.0054 | <0.0019 |
| OCT2 | 19.8 | 5.2 | Imax,u/IC50 ≥ 0.1 | 0.0082 | 0.0180 |
| MATE1 | 9.0 | 4.6 | Imax,u/IC50 ≥ 0.1 | 0.0181 | 0.0204 |
| MATE2‐K | >30 | >50 | Imax,u/IC50 ≥ 0.1 | <0.0054 | <0.0019 |
Abbreviation: NA, not applicable.
a
IC50 is calculated as described in Materials and Methods. See Supplemental Table 1 for transcellular transporter assay conditions.