What is the chemical difference in the urine between Vicodan and Percocet?

Vicodin is a class 3 narcotic, with hydrocodone. Percocet is a class 2 narcotic with oxycodone, which is a much stronger narcotic derivative. The risk of addiction varies with the dosage (small), with the length of time the drug is used and the personality of the patient. http://www.druginfonet.com/index.php?pageID=faq/faqvico.htm