If those high bleed numbers sound fishy, go to the head of the class. Plasmapheresis is not fun. Yet the program was so popular that inmates would stand in line for hours to do it. They did so knowing that they might get sick from it. Of course not.
Codeine is an opium derivative related to heroin.
In a word, HMA was trading narcotics for plasma. HMA used Percodan to bleed not twice but sometimes four times a week. Nobody wanted to buy from old sources in Africa and the Caribbean. Nobody wanted prison blood either, but it was a reliable source and it could be prettied up with names out of the phone book. For unscrupulous operators, this was a bonanza.