Enilospirone

Enilospirone

Enilospirone is a serotonin antagonist and reuptake inhibitor (SARI) that was under development by Eli Lilly in the 1990s for the treatment of depression and anxiety disorders. However, it did not reach the market due to poor clinical trial results.

History

Eli Lilly, a multinational pharmaceutical company, began the development of Enilospirone in the late 1980s. The drug was designed as a SARI, a class of drugs that inhibit the reuptake of serotonin, a neurotransmitter that plays a key role in mood regulation. SARIs are commonly used in the treatment of depression and anxiety disorders.

Pharmacology

As a SARI, Enilospirone works by blocking the reuptake of serotonin in the brain, thereby increasing the amount of serotonin available in the synaptic cleft. This is believed to help alleviate the symptoms of depression and anxiety. However, unlike other SARIs, Enilospirone also acts as a serotonin antagonist, meaning it blocks the action of serotonin at certain receptors in the brain. This dual action was thought to potentially offer advantages over other antidepressants, but clinical trials did not support this hypothesis.

Clinical Trials

Enilospirone underwent several phases of clinical trials in the 1990s. However, the results were disappointing. The drug did not demonstrate significant efficacy over placebo in treating depression or anxiety disorders. As a result, Eli Lilly decided not to pursue further development or seek regulatory approval for the drug.

Conclusion

Despite initial promise, Enilospirone did not prove to be an effective treatment for depression or anxiety disorders. Its development highlights the challenges and uncertainties inherent in drug development, even for large and experienced pharmaceutical companies like Eli Lilly.