Enrico Koenig might be able to help here: https://www.researchgate.net/profile/Enrico_Koenig?_sg=xF9K8YNX5lI53Sm5K44VEWA%2BO9pMmOKW%2Fs9%2F4aGbBCjG3SAeX4LhTZbI4eRNOBnT_5Qhm07w7WKiyQWASzHx0NQdk1gpA0V42izup69Eakllct0d85zJGKwKstoqblhUh_R4%2F4EsmYx9cUcO%2FBNhGXe20rAukuT39YTX%2BKJufAmSmZChC7aZjmETPfdOvv5u9E

This is a good paper:

A dangerously toxic new frog (Phyllobates) used by Emberá Indians of western Colombia, with discussion of blowgun fabrication and dart poisoning. Bulletin of the AMNH ; v. 161, article 2

Myers, Charles W.; Daly, John W.; Malkin, Borys.

Also, the late John W. Daly has a rich source of other papers on the topic. Search Google Scholar + Web of Science

”Bulletin of the AMNH ; v. 161, article 2 - Myers, Charles W.; Daly, John W.; Malkin, Borys”

any pdf available?

Dear Zslot, a pdf of that file is available at http://www.dendrobates.org/articles/Myers&Daly1978_P.terribilis.pdf.

Thanks to Gordon an Janine for the help! Was really useful