Well when I used to take vicodins to get high, if I redosed with more of them later in the day it wouldn't really get me high.
If you take even the smallest nap, you should be good to go. Morphine has always been a different high for me. I use it to stretch out the high of other opiates. But if you feel that it takes away from your high from other drugs, then I think you might need to nap to "reset" your brain.