Cocaine combined with capsaicin, an active ingredient in pepper spray, can be deadly, if research in mice is any indication. In the early 1990s, anecdotes of people dying after being doused with pepper spray puzzled researchers, until autopsies revealed many were on cocaine at the time. To look for a link between the two substances, a research team injected cocaine, capsaicin or both at once into the abdomens of several groups of about 30 mice. Injections allowed them to control the dose of capsaicin the mice received, which wouldn't have been possible if the mice were simply sprayed
. Equal doses of cocaine plus capsaicin killed about half the mice, compared to cocaine alone, which killed just a few. And a dose of cocaine high enough to kill half the mice on its own killed up to 90 percent when combined with capsaicin.
The researchers admit they don't really know how capsaicin and cocaine combine to make a lethal cocktail, but their research shows an interesting correlation. During their research, they
reviewed 26 autopsy reports and Californian police reports between 1993 and 1995 of people who died shortly after being subdued with pepper spray. They noted that 19 of them had evidence of psychostimulants in their blood and nine had cocaine. [The team] suspects that a fatal interaction takes place in the brain between capsaicin and psychostimulants
. Toxicologists not involved with the research say the results are certainly curious, but of course more research is necessary before jumping to conclusions. For one, the mice were injected with capsaicin while humans inhale pepper spray, so it's not clear how much capsaicin is absorbed into a person's bloodstream. Despite not knowing the underlying mechanism, scientists say their research, published in the journal Forensic Toxicology, suggests that police forces may need to rethink their use of pepper spray as a non-lethal weapon. Related Content: 80beats: Uncle Sam Promises to Lay Off Medical Marijuana Users 80beats: Military Taser Has 200-Foot Range—and Safety Concerns 80beats: One-Third of U.S. Cocaine Tainted With Dangerous Livestock Drug
Image: Wikimedia Commons / Stefan Kühn