Nicki, I answered this on another of your posts. The answer is the opiates more then likely. Fentanyl depressed the central nervous system (as does the hydrocodone in the norco) slowing the cardiovascular system...sometimes dramatically so in instances of overdose. This generally is the cause of fatigue...however opiates also cause insomnia and irregular sleep patterns and it also suppresses testosterone production in the body both cause fatigue.

He could also be suffering from PTSD, or CRF cancer related fatigue. Cancer takes a huge toll on the body emotionally & physically...but my guess is the pain meds as I had the same issues.

Eric