138452-21-8

The metabolite of seldane (terfenadine), fexofenadine, was launched in the USA. A histamine H₁ receptor antagonist, fexofenadine is more effect than its parent compound without the associated side-effects.

Sepracor (USA)

Anti-histamine

Fexofenadine HCl (Allegra) is a selective, specific H1 antagonist that is structurally related to the butyrophenone tranquilizer haloperidol. It is the active carboxylic acid metabolite of terfenadine (no longer commercially available in the United States). It binds mainly to the peripheral H1 receptors, with minimal crossing of the blood–brain barrier and hence minimal sedative effects. Fexofenadine lacks the cardiotoxic effects of its parent drug, terfenadine. However, it has been associated with increased QT interval, syncope, and ventricular arrhythmia in at least one susceptible patient with preexisting cardiovascular risk. To date, no significant interactions have been demonstrated with fexofenadine when administered concomitantly with azole antifungals or macrolide antibiotics. Indicated for seasonal allergic rhinitis and chronic idiopathic urticaria.

ChEBI:Fexofenadine hydrochloride is a diarylmethane.

Allegra

60 mg PO b.i.d.