Reference

Nisoxetine, developed in the 1970s, was a selective norepinephrine reuptake inhibitor (SNRI) initially investigated as an antidepressant. However, it was never marketed. The primary reason for its lack of commercial availability was likely due to the discovery of ocular toxicity in animal studies during clinical trials. This safety concern prevented nisoxetine from advancing further in the drug development process and being brought to market as a treatment for depression.

For more detailed information, you can refer to the article on DrugBank: DrugBank Online - Antidepressive Agents.