Cocaine is being cut with levamisol at the source and it cannot be removed through common methods of purification since they are very similar molecules (physical properties, chemistry). I was recently in Panama discussing this with a local drug addict. He was not aware of the contaminant but complained of all of the symptoms and disease states associated with the chronic intake of levamisol (which has a much longer half-life than cocaine, so it accumulates). Granted, his intake compared to a north american coke-head was bordering olympic caliber (a ball a day), but he was paying 20 bucks for a MASSIVE 1/8th and that stuff probably would have tested out at least around 90%. If the coke in Panama city has been cut with it, you can be sure that the stuff in the US has
Long story short, cocaine from the street is not a safe drug anymore. the VAST majority is poisoned, and the effects of this poison on humans hasn't even been fully realized yet. I work in harm reduction and we're starting to see clusters of cancers in our long term user community. This cannot be understated.
Try to find alternatives until this spiked-coke thing is over. Its not worth ruining your entire life to sort-kinda-not really get high and spend a ton of money.
Paradox