Pitolisant
Pitolisant. Histamine H3 receptor antagonist / inverse agonist; raises central histamine to promote wakefulness (narcolepsy). CYP2D6 + CYP3A4… Oral half-life 20 h.
Histamine H3 receptor antagonist / inverse agonist; raises central histamine to promote wakefulness (narcolepsy). CYP2D6 + CYP3A4 metabolism.
PK from FDA prescribing information (DailyMed setid 8daa5562-824e-476c-9652-26ceef3d4b0e): oral absorption ~90% (F 0.9), Vd 5–10 L/kg (~700 L), terminal t½ ~20 h, Tmax 3.5 h, CYP2D6/3A4. ka_hr 1.0 derived from Tmax 3.5 h (ke from t½ 20 h). PK stays on the approval document, which is the only source: no PubMed primary reports a pitolisant half-life, volume, absorption rate or bioavailability. THE LABEL WAS MISQUOTED. It says "The oral ABSORPTION of WAKIX is around 90%" — fraction absorbed, not bioavailability — and states no absolute bioavailability anywhere, so the stored F 0.9 was a misreading. F is pinned to 1 because the volume is explicitly APPARENT (V/F) and pairing the two would double-count absorption. ka 1.0 /h removed: it is a back-calculation from the label median Tmax of 3.5 h, not a stated figure. The half-life is a median with an individual spread of 7.5 to 24.2 h.
Pharmacokinetics
- Oral — t½ 20 h · F 100% · Vd 700 L
Sources: PMID:26084539