Hi eaglette,
I like to research stuff, and I have figured out most of the withdrawal symptoms for opiates (others may not align here) in terms of why they are happening on a physiologic basis.
I have NOT been able to figure out why complete and total exhaustion should accompany withdrawal. The only clue I have ever stumbled upon is something that an addiction medicine physician told me about danger signs for someone who is likely to become addicted. One of the major ones according to him is when drugs like opiates make the person energetic instead of sleepy, somnolent, mellowed out, lethargic, whatever. "Normal" people get sleepy and tired with opiates. Potential addicts get a rush of energy. That was me.
Armed with that information, I can only guess what causes the lethargy. A lot of opiate and other drugs will cause "rebound" effects when you stop them. In other words, now that the dopamine receptor sites are "empty", they cry to be filled, by causing symptoms that are the opposite of the "desirable" effects. So instead of euphoria, you have depression, instead of having constipation, you get diarrhea, instead of being pain free, you get pain. Maybe it is the same with the lethargy thing. The lethargy from opiate withdrawal lasted several WEEKS for me, and even at 5 months off, I still haven't regained my energy 100%. I hope that is to come.
So, I don't know if my thoughts help, because they are unscientific. The lethargy was one of the worst withdrawal effects for me, because I just don't have time to lay around. I had to get back to work quickly, but the first week I could barely crawl to the bathroom.
I took a brisk marina walk in the sun with my husband today. I remember those walks last year on opiates. The only way I could manage them was to pop several oxys a few minutes beforehand, and they would only last maybe an hour before I needed more. Not sustainable, that.
Anyone else have thoughts?
FT