ASSOCIATED PRESS: Nearly a third of all cocaine seized in the United States is laced with a dangerous veterinary medicine — a livestock de-worming drug that might enhance cocaine’s effects but has been blamed in at least three deaths and scores of serious illnesses. The medication called levamisole has killed at least three people in the U.S. and Canada and sickened more than 100 others. It can be used in humans to treat colorectal cancer, but it severely weakens the body’s immune system, leaving patients vulnerable to fatal infections.
Scientific studies suggest levamisole might give cocaine a more intense high, possibly by increasing levels of dopamine, the brain’s “feel-good” neurotransmitters. Drug Enforcement Administration documents reviewed by The Associated Press indicate that 30 percent of all U.S. cocaine seizures are tainted with the drug. And health officials 
told the AP that most physicians know virtually nothing about its risks.
Authorities believe cocaine manufacturers are adding the levamisole in Colombia, before the cocaine is smuggled into the U.S. and Canada to be sold as white powder or crack. Economic pressures may play a role. Decreased supply in the U.S. has raised cocaine prices and lowered street-level purity. Cocaine traffickers may believe levamisole adds an extra boost to an otherwise weakened product. Levamisole started showing up frequently in cocaine from Colombia in January 2008. By late last year, the DEA concluded that the spiked cocaine was in wide circulation. At the same time, hospitals around the country began noticing more cocaine users coming in with agranulocytosis, an illness that suppresses white blood cells necessary to fight off infections. MORE
RELATED: Once the cocaine enters the bloodstream, the magic begins. Aside from the euphoria and damaged respiratory epithelium, blood vessels constrict and heart rate goes up. This can kill you in several ways. A coronary spasm can equal an instant heart attack and you die pretty quickly a la River Phoenix. If you have underlying atherosclerosis, those blood vessels that are constricted are already pretty small and tend to close up entirely. That is why you tend not to see many cocaine aficionados past 50. If it doesn’t kill you right away, chronic use can lead to thickening of artery walls and narrowing of their lumens. If it doesn’t kill your kidneys first or lead to a stroke, it will exacerbate any coronary artery disease you have and kill you from a big MI. MORE