Millennium Research Institute

Relationship between the concentration of hydrocodone and its conversion to hydromorphone in chronic pain patients using urinary excretion data
NH Barakat, RS Atayee, BM Best, AJ Pesce
J Anal. Toxicol. 2012 May; 36 (4):257-264.
http://www.ncbi.nlm.nih.gov/pubmed/22511700