Vicodin is known to be the combination of two different drugs - hydrocodone, a pain reliever, and acetaminophen (better known as Tylenol). Vicodin ES also contains acetaminophen, but instead of hydrocodone, this contains Hydrocodone Bitartrate. The main difference between the two is the proportion of the drugs that can be found.
Some of the risks of taking these medications and the possible side effects that will be experienced can vary slightly depending on the amount that will be taken by the person. It is always important to know the proper dosage so that it will not cause potential issues later on.