There are 1 789 scinetific articles about Propoxyphene

If you go to Pub Med http://www.ncbi.nlm.nih.gov/pubmed and search for propoxyphene you get 1789 hits. If you search for dextropropoxyphene you get 1529. It is not so much if you consider that the substance has been around since 1953. 

From these 1789 hits we are the writers of 10 articles where we study propoxyphene/dextropropoxyphene from different point of views.

As far as I know no other researchers had written so many articles about DXP as we had done. I will just mention that. If you look for acetaminophen you get 15 062 and paracetamol  17 184 and for codeine you get 6 209, (the numbers are form September 2^nd 2011). Morphine gets 52 672 and methadone 11 738. Methadone is quite close to Dextropropoxyphene.

Some English researchers wrote this article; Co-proxamol and suicide: preventing the continuing toll of overdose deaths. http://qjmed.oxfordjournals.org/content/98/3/159.2.full

The researchers were; S. Simkin, K. Hawton, L. Sutton, D. Gunnel, O. Bennewith and N. KPU. They worked at the University of Oxford Centre for Suicide Research, Department of Psychiatry, Warneford Hospital, Oxford, Department of Social Medicine, University of Bristol, Bristol and Centre for Suicide Prevention, University of Manchester, Manchester, UK.

When they wrote their article they mention in Method: Literature search; Electronic searches of PsycINFO (1872–2003),MEDLINE (1966–2003), EMBASE (1980–2003) andCINAHL (1982–2003) were done, using search terms for co-proxamol, coproxamol, dextropropoxyphene and distalgesic combined with terms for overdose, self poisoning, suicide and attempted suicide. Four hundred and two papers were identified. From these we selected 42 English language papers where the contents of the abstract were relevant to the aims of this review. Twenty additional relevant papers were identified from reference lists.

This article is really very good research, and I repeat; they chose six of our articles, and the references were 73. We could feel very proud that they chose so many of our articles.

It was after this article was published the MHRA - (Medicines and Healthcare products Regulatory Agency), banned dextropropoxyphene.

In the US no such reserach has ever been done.

Medicines and Healthcare products Regulatory