What is "robalzotan"

Robalzotan (NAD-299, AZD-7371) is a selective antagonist at the 5-HT receptor. It was shown to completely reverse the autoreceptor-mediated inhibition of serotonin release induced by the administration of selective serotonin reuptake inhibitors like citalopram in rodent studies. It was subsequently investigated by AstraZeneca as a potential antidepressant but like many other 5-HT ligands was discontinued. Later on it was researched for other indications such as irritable bowel syndrome but was dropped once again.