Ultracet - Full prescribing information from RxList. - http://www.rxlist.com/cgi/generic3/ultracet.htm
Tramadol - Information from the RxList. - http://www.rxlist.com/cgi/generic/tramadol.htm
MedlinePlus Drug Information: Tramadol - Indications, precautions, and possible side effects. - http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a695011.html
DrugDigest: Tramadol ( Ultram ) - Information on dosage, usage, side effects, interactions, and drug comparisons, including generics when available. - http://www.drugdigest.org/DD/DVH/Uses/0,3915,675%7CUltram,00.html
Spine-Health - Information on use of Ultram (tramadol) in the treatment of back pain. Includes drug interaction, pregnancy risk and tolerance. - http://www.spine-health.com/topics/conserv/overview/med/med042.html