In three 2-week, multicenter, randomized, double-blind, placebo-controlled trials in subjects 12 to 68 years of age with seasonal allergic rhinitis (n=1634), fexofenadine hydrochloride 60 mg twice daily significantly reduced total symptom scores (the sum of the individual scores for sneezing, rhinorrhea, itchy nose/palate/throat, itchy/watery/red eyes) compared to placebo.
Radiolabeled tissue distribution studies in rats indicated that fexofenadine does
180 Allegra cross the blood-brain barrier. A dose of 5 mL of ALLEGRA Oral Suspension containing 30 mg of fexofenadine hydrochloride is bioequivalent to a 30 mg dose of ALLEGRA tablets. The 60 mg twice daily dose did not provide any additional benefit over the 30 mg twice daily dose in pediatric subjects 6 to 11 years of age. Fexofenadine hydrochloride was rapidly absorbed following oral administration of a single dose of two 60 mg capsules to healthy male subjects with a mean time to maximum plasma concentration occurring at 2.6 hours post-dose.
Each tablet contains 30, 60, or 180 mg fexofenadine hydrochloride (depending on the dosage strength) and the following excipients: croscarmellose sodium, magnesium stearate, microcrystalline cellulose, and pregelatinized starch. Pharmacokinetics in renally and hepatically impaired subjects and geriatric subjects, obtained after a single dose of 80 mg fexofenadine hydrochloride, were compared to those from healthy subjects in a separate study of similar design. The tablet formulations are bioequivalent to the capsule when administered
Zyrtec Clartin Allegra equal doses.
It is freely soluble in methanol and ethanol, slightly soluble in chloroform and water, and insoluble in hexane.
Similar reductions were observed for mean number of wheals and mean pruritus score at the end of the 24-hour dosing interval. Fexofenadine hydrochloride is a racemate and exists as a zwitterion in aqueous media at physiological pH. Onset of action for reduction in total symptom scores, excluding nasal congestion, was observed at 60 minutes compared to placebo following a single 60 mg fexofenadine hydrochloride dose administered to subjects with seasonal allergic rhinitis who were exposed to ragweed pollen in an environmental exposure unit. These studies indicate that ketoconazole or erythromycin co-administration enhances fexofenadine gastrointestinal absorption. Two 2-week multicenter, randomized, placebo-controlled, double-blind trials in 877 pediatric subjects 6 to 11 years of age with seasonal allergic rhinitis were conducted at doses of 15, 30, and 60 mg twice daily. In these studies, there was no additional reduction in total symptom scores with higher doses of fexofenadine hydrochloride up to 240 mg twice daily. Co-administration of 180 mg fexofenadine hydrochloride tablet with a Allegra Zyrtec fat meal decreased the mean area under the curve (AUC) and (Cmax) of fexofenadine by 21 and 20% respectively. This observed increase in the bioavailability of fexofenadine may be due to transport-related effects, such as p-glycoprotein.