Elbasvir
Elbasvir. HCV NS5A inhibitor — Zepatier component (50 mg elbasvir + 100 mg grazoprevir, once daily for genotype 1 or 4 HCV). Modest CYP3A4… Oral half-life 24 h.
HCV NS5A inhibitor — Zepatier component (50 mg elbasvir + 100 mg grazoprevir, once daily for genotype 1 or 4 HCV). Modest CYP3A4 substrate; not a strong inhibitor at clinical doses. The combo is taken with or without ribavirin depending on cirrhosis status and prior treatment failure. PK (Zepatier label, 50 mg PO qd SS): Cmax 121 ng/mL, AUC 1920 ng·h/mL, Tmax 3 h (range 3-6), t½ 24 h, F 32%. High-fat meal effect on elbasvir is modest (~15%). Steady state by ~6 days. CYP3A4 substrate; strong inhibitors require dose adjustment.
PK: EVERY STORED LABEL FIGURE VERIFIES AND ONLY THE ABSORPTION RATE FAILS. The Zepatier label states "elbasvir peak concentrations occur at a median Tmax of 3 hours (range of 3 to 6 hours)", "The absolute bioavailability of elbasvir is estimated to be 32%", and a "geometric mean apparent terminal half-life ... approximately 24 ... hours", all of which this record carries correctly; ka 0.5 predicted a peak at 6.05 h. CLASS 6 IS ACQUITTED IN AN UNUSUAL WAY AND IT MUST BE RECORDED: the label DOES publish an apparent volume, "approximately 680 L ... based on population pharmacokinetic modeling", AND THAT IS NOT WHAT IS STORED. The stored 288 L was back-solved to reproduce the label exposure and does so to 0.2%. SUBSTITUTING THE PUBLISHED 680 L WOULD MAKE EXPOSURE 33% TOO HIGH, because that population value belongs to a multi-compartment fit. The back-solve is right; it simply has no citation, and the source_label string does not claim one. The stored values are the co-formulated clinical state. A reference on this record reports 18 h rather than the stored 24; it is the only indexed abstract on either component and must not be mistaken for the source.
Pharmacokinetics
- Oral — t½ 24 h · F 32% · ka 1.3 h⁻¹ · Vd 288 L
Sources: PMID:32104104