[Demonstration of clinical bioequivalency of teldane and feliberal using a bioassay with intradermal histamine challenge in healthy volunteers]. / Demostración de la bioequivalencia clínica de Teldane y Feliberal mediante un bioensayo con reto de histamina intradérmica en voluntarios sanos.

To demonstrate the bioequivalence of two terfenadine formulations, a clinical-equivalence trial was performed. The antihistaminic's ability to prevent the response to intradermal histaminic challenge was herein assessed. Twelve healthy volunteers underwent a randomized, double blind, cross over trial with seven-day treatments. Dermal response to histamine concentrations of 0, 1, 2, 5 and 10 mcg was determined by measuring the wheal produced on the deltoid area. Measurements were made 72 hours prior to terfenadine administration, 1 hour after the first dose and 11 hours after second and last doses of each treatment. Both formulations showed the same latency, extent and duration in protective effect against histaminic challenge. This confirms the clinical equivalence of the two formulations and suggests that they have a similar bioavailability.