About Allegra.

Fexofenadine has been shown to exhibit minimal (ca. 5%) metabolism. However, co-administration of Fexofenadine hydrochloride with either ketoconazole or erythromycin led to increased plasma concentrations of Fexofenadine. Fexofenadine had no effect on the pharmacokinetics of either erythromycin or ketoconazole. In 2 separate studies, Fexofenadine hydrochloride 120 mg twice daily (240 mg total daily dose) was co-administered with either erythromycin 500 mg every 8 hours or ketoconazole 400 mg once daily under steady-state conditions to healthy volunteers (n=24, each study). No differences in adverse events or QTc interval were observed when subjects were administered Fexofenadine hydrochloride alone or in combination with either erythromycin or ketoconazole.

The changes in plasma levels were within the range of plasma levels achieved in adequate and well-controlled clinical trials.

The mechanism of these interactions has been evaluated in in vitro, in situ, and in vivo animal models. These studies indicate that ketoconazole or erythromycin co-administration enhances Fexofenadine gastrointestinal absorption. This observed increase in the bioavailability of Fexofenadine may be due to transport-related effects, such as p-glycoprotein. In vivo animal studies also suggest that in addition to enhancing absorption, ketoconazole decreases Fexofenadine gastrointestinal secretion, while erythromycin may also decrease biliary excretion.

Seasonal Allergic Rhinitis

Fexofenadine Hydrochloride Tablets are indicated for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 6 years of age and older. Symptoms treated effectively were sneezing, rhinorrhea, itchy nose/palate/throat, itchy/watery/red eyes.

Chronic Idiopathic Urticaria

Fexofenadine Hydrochloride Tablets are indicated for treatment of uncomplicated skin manifestations of chronic idiopathic urticaria in adults and children 6 years of age and older. It significantly reduces pruritus and the number of wheals.

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 post-dose. After administration of a single 60 mg capsule to healthy volunteers, the mean maximum plasma concentration was 131 ng/mL. Following single dose oral administrations of either the 60 and 180 mg tablet to healthy adult male volunteers, mean maximum plasma concentrations were 142 and 494 ng/mL, respectively. The tablet formulations are bioequivalent to the capsule when administered at equal doses. Fexofenadine hydrochloride pharmacokinetics are linear for oral doses up to a total daily dose of 240 mg (120 mg twice daily). The administration of the 60 mg capsule contents mixed with applesauce did not have a significant effect on the pharmacokinetics of Fexofenadine in adults.

Co-administration of 180 mg Fexofenadine hydrochloride tablet with a high fat meal decreased the AUC and Cmax of Fexofenadine by 21 and 20% respectively.