What's the difference between brand name and generic vicodin?

Cost: To meet fda rules, all active ingredients in generic medications must be identical to active ingredients in brand-name meds. Generics, however, may use different 'inactive' ingredients: different dyes, binding agents, etc. Since the inactive ingredients 'do nothing, ' the meds are equivalent.The only difference, in theory, is some patients may be allergic to some inactive ingredients & not others.