Loratadine
Loratadine. Second-generation H1 antagonist — minimal BBB penetration → low sedation. Active descarboethoxy metabolite (desloratadine) has long… Oral half-life 6 h.
Second-generation H1 antagonist — minimal BBB penetration → low sedation. Active descarboethoxy metabolite (desloratadine) has long half-life supporting once-daily dosing.
PK: A 12.4x EXPOSURE ERROR RESTING ON A SINGLE INDEFENSIBLE VOLUME. Its own citation gives "AUC(0-infinity)) was (47+/-49) microg x h x L(-1) for LOR" at 20 mg, which is a clearance of 425.5 L/h against the stored 34.4, and a second study at 40 mg agrees at 417-500. V 119 L appears in no abstract, and its own citation implies 3683 L — thirty-one times larger. IT IS ALSO BYTE-IDENTICAL TO canagliflozin V_L, where that record notes confirm it is verbatim and intravenous-derived; the direction is unprovable and it may equally be loratadine textbook figure in L/KG stored as litres, but 119 L is indefensible either way. F 0.4 is likewise absent from the abstract, whose nearest numeral is an AUC RATIO, and loratadine has no intravenous form at all: "the absolute bioavailability is unknown because no intravenous formulations are available". F is pinned to 1 and the volume becomes the apparent one its own citation implies from verbatim dose, AUC and half-life. THE COST IS STATED: exposure becomes exact and the peak falls to about a quarter of observation, which is unavoidable — the published AUC-to-Cmax ratio for this drug is BELOW the floor a one-compartment model can produce at any parameter choice. ka 2.0 is dropped; it is shared with thirteen other records.
Pharmacokinetics
- Oral — t½ 6 h · F 100% · Vd 3683 L
Sources: PMID:12852841