Eighty-two percent of seized cocaine contains levamisole, according to an April 2011 report by the U.S. Drug Enforcement Administration. Why dealers would stretch their stash with levamisole instead of the more traditional fillers, like baking soda, is unclear, although studies in rats suggest the drug acts on the same brain receptors as cocaine. So it might be added to enhance or extend the cocaine’s euphoric effects on the cheap.
Despite the widespread contamination, not all of the country’s cocaine users experience the flesh-rotting reaction. It appears that some are more vulnerable to tainted cocaine’s effects.
“We don’t know who this is going to happen to,” said Dr. Lindy Fox, the University of California, San Francisco, a dermatologist who first connected the gruesome lesions on cocaine users to levamisole. Similarly, some patients have more extreme reactions than others. Fox said she once saw a photo of a man whose entire body, face included, was black with dying flesh.