As to why it isn't available in the US, here is one explanation. Not familiar with the journal, I found this on a Google search:
Online forum users are quick to wonder why tianeptine hasn’t reached American
markets, if it seems to work as well as conventional antidepressants, apparently
has fewer side effects, and has been approved in much of Europe, Latin America,
and Southeast Asia. In the United States, the intricacies of international
patent law have made it financially difficult for tianeptine to get FDA
approval. Tianeptine is decades old, but it wasn’t until the late ‘80s and ‘90s
that its antidepressant effects were discovered. Tianeptine is now off-patent,
meaning that if Servier were to get the drug approved, any company could make
and market the drug on their ticket. Given this, it isn’t financially worth it
for Servier, or any other company, to sponsor the FDA clinical trials required
for drug approval. It’s worth noting that it may be possible for tianeptine to
be repatented with a different use in mind, such as irritable bowel syndrome. If
this were the case, it would be lucrative for a company to sponsor its FDA
application and tianeptine could be prescribed off-label for depression in the
United States.
http://hypocritereader.com/13/antidepressants