Siramesine (or Lu 28-179) is a sigma receptor agonist, selective for the σ2 subtype.

[1] In animal studies, siramesine has been shown to produce anxiolytic[2] and antidepressant[3] effects.

It was developed by the pharmaceutical company H Lundbeck for the treatment of anxiety,[4] although development was discontinued after clinical trials showed a lack of efficacy in humans.

Siramesine has been shown to produce an enhanced antidepressant effect when co-administered with NMDA antagonists.

[5] It has also been used to study the σ2 activity of cocaine,[6] and has been shown to produce anticancer properties both in vitro[7] and in vivo.