Ketanserinol (R 46742) is a metabolite of Ketanserin . Ketanserinol is a competitive antagonist of the effects of 5-HT in both arteries. The KB values are 6.5 for large coronary arteries and 6.4 for pulmonary arteries.
References:
[1]. Frenken M, et al. Interaction of ketanserin and its metabolite ketanserinol with 5HT2 receptors in pulmonary and coronary arteries of calf. Naunyn Schmiedebergs Arch Pharmacol. 1984 Jul;326(4):334-9.