A question about tolerance to various effects of opiates/opioids

[Forthesevenlakes]

Any opiate user knows that tolerance can build quickly to the pleasurable effects of these drugs, requiring more of the drug in order to get a similar pleasant feeling. SWIM has been wondering lately about the tolerance to negative or neutral side effects to these drugs, too. Some lab rats do not think that tolerance really builds to the negative/neutral side effects, and others say that some side effects seem to go away, while others don't. SWIM thinks that while one might be less likely to notice the absence of a negative sensation than the absence of a positive one, tolerance could certainly build to the various effects.

So, what SWIM is wondering is, what are your experiences with tolerance?

How long did it take to build tolerance to different effects of opiates (positive, negative, or neutral), and with what dosages? Everyone is different and SWIM doesn't expect people to react the same way to these drugs, but perhaps a consensus on tolerance to some effects could be reached.

SWIM first got started thinking about this when a lab rat mentioned to him that they stopped getting constipation from opiates after a couple months of use. SWIM has been using opiates, at least occasionally, for many years, and it seems that the little bastards still make him constipated. However, after using opiates once a week for about a month, he stopped getting the urinary retention problem that affects some users.

Any input? SWIY does not have to be a daily or current user of opiates to answer this question, just some info on the effect that one gained tolerance to, the time taken to reach this tolerance, the dosages, and when or if this tolerance disappeared after use stopped would be interesting to SWIM, and perhaps he could compile it into a smooth sticky thread or table when all is said and done.