Blonanserin, sold under the brand name Lonasen, is a relatively new atypical antipsychotic (approved by PMDA in January 2008)[2] commercialized by Dainippon Sumitomo Pharma in Japan and Korea for the treatment of schizophrenia.

[3] Relative to many other antipsychotics, blonanserin has an improved tolerability profile, lacking side effects such as extrapyramidal symptoms, excessive sedation, or hypotension.

[8] Blonanserin has a relatively high affinity towards the 5-HT6 receptor perhaps underpinning its recently unveiled efficacy in treating the cognitive symptoms of schizophrenia.

[10] Specifically, the addition of hydroxyl groups to blonanserin's unique eight membered ring results in the (R) stereoisomer of the compound demonstrating increased affinity for the indicated targets.

[1] Single fasting doses are safe and the effects of feeding intake are possibly explained by an interaction between blonanserin and cytochrome P450 3A4 in the gut.