Is there codeine in vicodin?

See http://opioids.com/hydrocodone/vicodin.html

Text below is copied from the above site...

"First, a primer: Hydrocodone was first manufactured in the early 1920s by the
German pharmaceutical company Knoll. As its name denotes, hydrocodone is the
codeine molecule with a hydrogen atom attached. At the time, Knoll believed
hydrogenizing codeine might make it less toxic and easier on the stomach.
At about the same time, the U.S. government was searching for an answer to
the growing "opium problem," the thousands of middle-class Americans who
became hooked on opium derivatives then used as cough suppressants. In 1929,
the U.S. Bureau of Social Hygiene gave the National Research Council several
million dollars to study various new compounds like hydrocodone, seeking to
find a less addictive painkiller."

Additional info:

Just wanted to add to the very nice and accurate information above. Hydrocodone has codeine in it but is formulated specially to make Hydrocodone. Hydrocodone is semi synthesized where as codeine all comes from morphine or poppy. I also wanted to mention that taking any opioid like hydrocodone with another opioid like codeine can be fatal and combining such prescription drugs on your own even at the smallest amounts can cause side effects including seizures. If you take a look at the chemical formula of Codeine and Hydrocodone it is identical C₁₈H₂₁NO_3.