Etifoxine

Etifoxine (INN, also known as etafenoxine; trade name Stresam) is an anxiolytic and anticonvulsant drug developed by Hoechst in the 1960s. It is used in anxiety disorders and to promote peripheral nerve healing. It has similar effects to benzodiazepine drugs, but is structurally distinct and does not bind to the benzodiazepine receptor. It is more effective than lorazepam as an anxiolytic, and has fewer side effects.

Etifoxine has been associated with acute liver injury.

Mechanism of action

Unlike benzodiazepines, etifoxine appears to produce its anxiolytic effects by binding to β2 and β3 subunits of the GABA_A receptor complex, and so is acting at a different target site to benzodiazepines, although the physiological effect that is produced is similar to that of benzodiazepines. This difference in binding means that etifoxine can be used alongside benzodiazepines to potentiate their effects without competing for binding sites, however it also means that the effects of etifoxine are not reversed by the benzodiazepine antagonist flumazenil. (S)-Etifoxine is currently being investigated as a pain management medication. It has shown promise for chemotherapy induced pain as well as neuropathic pain, with little or no sedating side effects.