the simple scenerio of someone exchanging sex for drugs isn't necessarily the entire issue here, and too few people are smart enough to clarify this. as a 19 year old woman who uses drugs, there have been endless opportunity for me to use my body to score cheaper or free drugs, and after about three years of experimentation and usage, it's become clear to me that there is a definite difference between male users and female users, and sometimes, just being a woman user defines you as a "drug slut"...
obviously, a woman or man who is desperate enough for drugs to exploit their body in return for drugs is sad and unfortunate, and before we, as a society, point fingers and label "slut" and "whore", there is no real examination of the situations leading up to this... there is a strong correlation with drug use and psychological issues (not a proved causation, though) and it's easy for society to sit here and say, "you're a dirty coke whore" because it's easier to blame and persecute that take the time to understand or even care...
another note, while some may claim they'd never put their bodies to shame like that, they'd never use sex as means of payment for drugs, there are plenty of other opportunites to sell yourself short, exploit your personality, character or morals to receive drugs... if you could steal money from your workplace without a trace and use it towards drugs, you're still just as "pathetic" as a "drug slut"... or if you injured another person to get ahead and get drugs, you're still hurting yourself and someone else...
i am, in no way, condoning or approving or agreeing with using sex as payment for drugs, but before we point fingers, label them as "scum of our earth", it's important also look at ourselves and question what we'd do, if push came to shove, to get drugs...