QTc interval prolongation by fexofenadine in healthy human volunteers and its correlation with plasma levels of fexofenadine: A demonstration of anticlockwise hysteresis.

Aim: The study was designed to establish relationship between the plasma concentration and QTc interval prolonging effect of fexofenadine and demonstrate the phenomenon of anticlockwise hysteresis.

Materials And Methods: Six subjects were given fexofenadine 60 mg tablet orally under stable conditions, and their drug concentrations were measured at regular intervals. At predetermined time, their ECGs were recorded.