Vicodin Addiction
Vicodin addiction occurs when continued use is needed to avoid withdrawal symptoms. Tolerance is initially manifested by a reduced duration of pain relief, followed by decreases in the actual intensity of pain relief. It is not uncommon to see patients who began treating their pain with 4-6 vicodins per day and have progressed to quantities in excess of 30-40 pills per day.

After prolonged opiate use, the nerve cells in the brain, which would otherwise produce endogenous opiates (natural painkillers, or endorphins), cease to function normally. The body stops producing endorphins because it is receiving opiates instead. The degeneration of these nerve cells results in the user's physical dependency to an external supply of opiates.