Ritanserin

Ritanserin is a serotonin antagonist with possibilities for the treatment of many neurological disorders.

When used together with typical antipsychotics in the treatment of schizophrenia is able to decrease negative symptoms and adds some "atypicality" as parkinsonism is slightly decreased.

Pharmacology
Ritanserin acts as a 5-HT2A and 5-HT2C receptor antagonist, with higher affinity for the former site.