Desloratadine
Desloratadine. Active descarboethoxy metabolite of loratadine — a third-generation H1 antagonist with the same minimal CNS penetration but… Oral half-life 27 h.
Active descarboethoxy metabolite of loratadine — a third-generation H1 antagonist with the same minimal CNS penetration but cleaner pharmacokinetics. Once-daily dosing for allergic rhinitis + chronic urticaria.
PK: THE HEALTHIEST RECORD IN ITS GROUP, AND THE NUMBERS ARE LEFT ALONE — it reproduces a verbatim "AUC(24h) 56.9 microg.h/L" to within 2.2%, which is the best arithmetic agreement in that group. Only the volume provenance moves, to the verbatim "particularly large for desloratadine (approximately 49 l/kg)", a 2% change. THAT SAME PAPER ALSO SETTLES CLASS 6 IN THE ACQUITTAL DIRECTION AND SOURCES THE F: it calls the volume APPARENT and states "the estimation for fexofenadine is at least 33%; NO ESTIMATION WAS FOUND FOR DESLORATADINE", so pinning F to 1 beside an apparent volume is correct and deliberate rather than a gap. THE DEFECT ON THIS RECORD IS IN OUR OWN PROSE: its effect-compartment note describes a "2-6 h window" that belongs to FEXOFENADINE — the cited study is a fexofenadine-versus-desloratadine comparison, and desloratadine own verbatim onset in it is 5 hours. The stored keo is right; simulated effect-site peak lands at 8.2 h, inside the verbatim "from 6 to 10 hours".
Pharmacokinetics
- Oral — t½ 27 h · F 100% · ka 1.252 h⁻¹ · Vd 3430 L
Sources: PMID:12169042, PMID:17390761, PMID:12167464, PMID:15312146