Your withdrawal experiences with opiates

[AceOvArts]

Could you share your feelings and what you go through when withdrawing from opiates.
Last week was what I think was SWIMs first opiate withdrawl. He told me he had been using Vicodin for about 3 or 4 weeks almost daily, increasing his tolderence to about 6-8 7.5/325s a day. When he withdrew from this, his first day he felt no real badness but the following 3 days got progressively worse then over the next 3 days or so got better.
On his worst day he got home from a poor day at work only to argue with his lady friend. He started to feel like he has felt only a handful of times in his life before. Dreams becoming nightmareish and awaking feeling scared. Feeling like he knew deeply about the cycle of life, even thoughts of knowing about his own future death. He told me he doesnt want to get too deeply into specifics at this time in this thread (the thoughts really scare the hell out of him). He suffered a sort of runny nose and cough, but dont know if its just the usual bugs that are going about at this time of year.
On his worst day he swore never to take drugs recreationally again, this being his usual respose to come downs.
He is wondering if this was withdrawl or viral illness, would vicodin at this level produce such a withdrawl.
Please share your experiences.
thanks