Temanogrel (APD791) is a highly selective antagonist of the 5-HT2A receptor (Ki: 4.9 nM).

5-HT2A:4.9 nM (ki)

Temanogrel inhibits inositol phosphate accumulation (IC50: 5.2 nM). Temanogrel shows effective inhibition of serotonin mediated amplification of ADP-stimulated human and dog platelet aggregation (IC50=8.7 and 23.1 nM, respectively). Pretreatment of aortic rings with Temanogrel prevents the vasoconstriction caused by 20 μM 5-HT in a concentration-dependent manner. Preincubation with Temanogrel also significantly inhibits the 5-HT-stimulated DNA synthesis (IC50: 13±7 nM) [1][3].

Plasma Temanogrel levels show a rapid and sustained increase, averaging 25.5±4.1, 28.7±4.6, and 31.2±4.5 ng/mL, respectively, at 10 min, 1.25 h, and 2.25 h after the start of treatment in dogs assigned to receive Temanogrel. There are no differences in heart rate or mean arterial pressure between saline-treated and Temanogrel-treated groups at any time during the experiment [3].