PDR Assignment for Week No. _Example 1 by CCG__
Page no. in 1997 PDR: Not in the PDR, but on p. 411 of Physcian's Drug Handbook (97)
Drug Name (Trade): Allegra
Drug Name (Generic): Fexofenadine hydrochloride
Brief Description:
Fexofenadine hydrochloride, the active ingredient of
ALLEGRAª, is a histamine H1-receptor antagonist.
ALLEGRAª is formulated as capsules for oral
administration. Each capsule contains 60 mg fexofenadine
hydrochloride and the following excipients: croscarmellose
sodium, gelatin, lactose, microcrystalline cellulose, and
pregelatinized starch.
Clinical Pharmacology:
Fexofenadine, a metabolite of terfenadine (aso known as Seldane {see Allegra Press Release and a Seldane Press Release for important info about Seldane}, is an antihistamine with selective peripheral H1-receptor antagonist activity. Fexofenadine inhibited antigen-induced bronchospasm in sensitized guinea pigs and histamine releasefrom peritoneal mast cells in rats. In laboratory animals, no anticholinergic or alpha1-adrenergic-receptor blocking effects were observed. Moreover, no sedative or other central nervous system effects were observed. Radiolabeled tissue distribution studies in rats indicated that fexofenadine does not cross the blood-brain barrier.
Pharmacokinetics:
Fexofenadine hydrochloride was rapidly absorbed following oral administration of a single dose of two 60-mg capsules to healthy male volunteers with a mean time to maximum plasma concentration occurring at 2.6 hours postdose. After administration of a single 60-mg dose as an oral solution to healthy subjects, the mean plasma concentration was 209 ng/mL. Mean steady-state peak plasma concentrations of 286 ng/mL were observed when healthy volunteers were administered multiple doses of fexofenadine hydrochloride (60 mg oral solution every 12 hours for 10 doses). Fexofenadine pharmacokinetics were linear for oral doses up to 120 mg twice daily. Although the absolute bioavailability of fexofenadine hydrochloride capsules is unknown, the capsules are bioequivalent to an oral solution. The mean elimination half-life of fexofenadine was 14.4 hours following administration of 60 mg, twice daily, to steady-state in normal volunteers. The pharmacokinetics of fexofenadine hydrochloride in seasonal allergic rhinitis patients were similar to those in healthy subjects. Peak fexofenadine plasma concentrations were similar between adolescent (12-16 years of age) and adult patients. Fexofenadine is 60% to 70% bound to plasma proteins, primarily albumin and alpha1- acid glycoprotein.
Indications:
ALLEGRAª is indicated for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 12 years of age and older. Symptoms treated effectively include sneezing, rhinorrhea, itchy nose/palate/throat, itchy/watery/red eyes.
Contraindications:
ALLEGRAª is contraindicated in patients with known hypersensitivity to any of its ingredients.
Note:
How do the structures
of cetrizidine (Zyrtec), fexofenadine (Allegra), and
terfenadine (Seldane) compare?
Allegra Prescribing Information
Molecular Pharmacology Home Page
PDR Form