So I tried vicodin for the first time yesterday, with no previous experience with opiates. I felt like nothing at all happened. I took 12.5 mg initially to get an idea of what it would feel like, but when I felt like nothing happened, so an hour later I took 7.5 mg more. Still felt like nothing happened, so half an hour later I took 7.5 more for a total of 27.5 mg of hydro. After 3 hours, all I noticed was a loss of balance and I got tired. What's up with that? Do they just affect me differently? Do I need to take more? For reference, I am 170 lbs.