Quetiapine-d4 (hydrochloride) (ICI204636-d4 (hydrochloride)) is deuterium labeled Quetiapine. Quetiapine (ICI204636) is a 5-HT receptors agonist with a pEC50 of 4.77 for human 5-HT1A receptor. Quetiapine is a dopamine receptor antagonist with a pIC50 of 6.33 for human D2 receptor. Quetiapine has moderate to high affinity for the human D2, HT1A, 5-HT2A, 5-HT2C receptor with pKis of 7.25, 5.74, 7.54, 5.55. Antidepressant and anxiolytic effects[1][2].