Rexulti theoretically has a lower risk of extrapyramidal symptoms and prolactin elevation, because of its enhanced serotonin antagonism Rexulti has a high affinity for serotonin 5HT1A receptors, where it is a partial agonist, and 5HT2A receptors, where it is an antagonist. Abilify affects the same receptors, but to a lesser extent. This may give Rexulti an advantage over Abilify.