Different strains contain different cannabanoid profiles, meaning they will effect each user's cannabanoid recepetors differently.

Thus said, it is highly likely that you ingested a cannabanoid profile not normal to your regular cannabis, giving you a much more interesting euphoric high.

I can almost gurantee that nobody on the street will lace their weed with any other sort of drug, the reason being their is absoultly no benefit. Cannabis is one of the cheapest drugs on the market, so it would be idoitic to lace it with a more expensive drug. It just simply doesnt happend.

I have however heard of street dealers doing disgusting things to their pot to make it weigh more (misting, soaking in embalming fluid, and sprinkling fine glass onto the pot) or more commonly they will have cannabis that is infected with pests or mildew/mold.

Street prices will ALWAYS be cheaper, but than again you are risking legalities and quality, not to mention safety.

However, there are many good people growing in the community and supplying the medical patients and of course I am not speaking of them, but more along the lines of the grab and go dealers that will sell anything, not just medicinal cannabis to qualified patients.