Vilazodone Hydrochloride (EMD 68843 Hydrochloride) is a serotonin transporter (SER) inhibitor and 5-HT1A receptor partial agonist.

Administration of 5-HT1A receptor agonists produce a characteristic behavioral syndrome that includes changes in posture, hind limb reduction, head weaving, tremors, forepaw treading, and straub tail. In the rat ultrasonic vocalizations test, stress-induced vocalizations are inhibited by Vilazodone Hydrochloride (EMD 68843 Hydrochloride) (55 mg/kg po) at 120 and 210 min post dose. Vilazodone Hydrochloride (EMD 68843 Hydrochloride) (20-40 mg/kg ip), administered acutely or prophylactically (1 week prior to behavioral testing), attenuated stress induces potentiated startle but has no effect on stress potentiated anxiety response in the elevated plus maze. Interestingly, a lower dose of 10 mg/kg of Vilazodone Hydrochloride (EMD 68843 Hydrochloride) has the opposite effect in the startle response, indicating a somewhat unexplained bidirectional effect, and all doses produce a potentiation of the startle-induced stress response possibly suggestive of an anxiogenic-like response[1]. Vilazodone Hydrochloride (EMD 68843 Hydrochloride) also represents another option for the treatment of MDD[2].

References:
[1]. Lee A. Dawson et al. Vilazodone: A 5-HT1A Receptor Agonist/Serotonin Transporter Inhibitor for the Treatment of Affective Disorders CNS Neuroscience & Therapeutics Volume 15, Issue 2, pages 107-117, June 2009
[2]. Reed CR, Kajdasz DK, Whalen H, Athanasiou MC, Gallipoli S, Thase ME.The efficacy profile of vilazodone, a novel antidepressant for the treatment of major depressive disorder.Curr Med Res Opin. 2012 Jan;28(1):27-39.