>>11933997I'm sure some smartypants will correct me if I'm wrong but I don't think this has been mapped out fully. Diarrhea symptoms are fairly easy to explain by cAMP hypofunction in intestinal cells, but the rise in temperature is more difficult to explain. If it does in fact occur (instead of being a perceived change of temperature only on the part of the addict) I'd guess it's because opioid receptors are strongly expressed in the hypothalamus which is involved in the regulation of body temperature.
A general rule of thumb is that withdrawal symptoms are the inverse of the physiological effect of the drug itself. Since opioids have a very strong suppressive effect on the sympathetic nervous system by virtue of the opioid receptor distribution, it stands to reason that withdrawal activates the parasympathetic nervous system. Hence, muscle tension and increase in temperature.
Apparently men can also experience spontaneous ejaculation. I have no fucking clue how the hell that could happen though.
