Table 1.
Pharmacokinetic characteristics of rifapentine and rifampicin after oral administration
| PK properties | Rifapentine | Rifampicin |
|---|---|---|
| Intestinal absorption | Increases with food | Decreases with food |
| Substrate of ABCB1 | Yes | Yes |
| Inducer of ABCB1 | No | Yes |
| Bioavailability after administration per os (%) | ~70 | ~90 |
| Cmax (h) | 2.5–5.5 | 2–4 |
| Plasma protein binding (%) | ~99 | ~80 |
| Biotransformation | Hepatic esterase | Hepatic esterase |
| CYP450 induction | 3A4, 2C8/9 | 1A2, 3A4, 2C8/9/19 |
| Magnitude of CYP450 induction | ++ | +++ |
| Auto-induction | No | Yes |
| Half-life (h) | ~10–15 | ~2–5 |
| Main elimination route | Hepatic | Hepatic |
| Renal elimination (%) | ~15 | ~30 |
Abbreviations: PK, pharmacokinetic; Cmax, maximal concentration; CYP, cytochrome P.