Esketamine is produced from ketamine, an anesthetic agent that was historically used for sedation purposes. The S-enantiomer of ketamine, esketamine, is more effective at stimulating the N-methyl-D-aspartate (NMDA) glutamate receptor than the R-enantiomer.
Ketamine’s antidepressant effects are thought to be produced by its action on the NMDA receptor, which results in the development of new neural connections (synapses). For this reason, the S-enantiomer was developed to treat Depression with the introduction of Spravato.
To specifically treat depression, the FDA recently approved an esketamine nasal spray. Esketamine has a higher potency, low doses still provide good clinical effects with minimal side effects.
Insurance companies do provide coverage for Spravato.