Molecules to Medicine: Should pepper spray be put on (clinical) trial?
Pepper spray is all over the news, following the Occupy Wall Street protests, particularly following the widely disseminated images and videos of protestors being sprayed in NY, Portland, and UCDavis.
Before that, I knew and occasionally used its main ingredient, capsaicin, as a treatment for my patients with shingles, an extremely painful Herpes zoster infection. And I knew about the many of the serious side effects of pepper spray, well-described by Deborah Blum.
Recently though, other questions arose, like “How was this learned?”. So off I went, looking for clinical trials to see what, if anything, had been studied, beyond the individual patient, poison control, and toxicology reports. Here’s what I learned:
There are reports of the efficacy of capsaicin in crowd control, but little regarding trials of exposures. Perhaps this is because pepper spray is regulated by the Environmental Protection Agency, as a pesticide and not by the FDA.
The concentration of capsaicin in bear spray is 1-2%; it is 10-30% in “personal defense sprays.”
While the police might feel reassured by the study, “The effect of oleoresin capsicum “pepper” spray inhalation on respiratory function,” I was not. This study met the “gold standard” of clinical trials, in that it was a “randomized, cross-over controlled trial to assess the effect of Oleoresin capsicum (OC) spray inhalation on respiratory function by itself and combined with restraint.” However, while the OC exposure showed no ill effect, only 34 volunteers were exposed to only 1 sec of Cap-Stun 5.5% OC spray by inhalation “from 5 ft away as they might in the field setting (as recommended by both manufacturer and local police policies).”
By contrast, an ACLU report, “Pepper Spray Update: More Fatalities, More Questions” found, in just two years, 26 deaths after OC spraying, noting that death was more likely if the victim was also restrained. This translated to 1 death per 600 times police used spray. (The cause of death was not firmly linked to the OC). According to the ACLU, “an internal memorandum produced by the largest supplier of pepper spray to the California police and civilian markets” concludes that there may be serious risks with more than a 1 sec spray. A subsequent Department of Justice study examined another 63 deaths after pepper spray during arrests; the spray was felt to be a “contributing factor” in several.
This article has a graphic showing the heat unit levels of capsicum. Beginning with Bell Peppers with 0 heat units to Pure Capsicum with 15,000,000 heat units. US. Grade Pepper Spray has between 2,000,000 and 5,500,000 heat units. A Jalepello Pepper has between 3,500 and 8,000 to give you an idea.
Their paper focuses mostly, though, on the dangerous associated with pepper-based compounds. In 1997, for instance, researchers at the University of California-San Francisco discovered that the “hot” sensation of habaneros and their ilk was caused by capsaicin binding directly to proteins in the membranes of pain and heat sensing neurons. Capsaicins can activate these neurons at below body temperature, leading to a startling sensation of heat. Repeated exposure can wear the system down, depleting neurotransmitters, reducing the sensation of the pain. This knowledge has led to a number of medical treatments using capsaicins to manage pain.
In fact, in 1999, the ACLU asked the California appeals court to declare the use of pepper spray to be dangerous and cruel. That request followed an action by northern California police officers against environmental protestors – the police were accused of dipping Q-tips into OC spray and applying them directly to the eyes of men and women engaged in an anti-logging protest.
“The ACLU believes that the use of pepper spray as a kind of chemical cattle prod on nonviolent demonstrators resisting arrest constitutes excessive force and violates the Constitution,” wrote association attorneys some 13 years ago.
Yesterday, the University of California-Davis announced that it was suspending two of the police officers who pepper-sprayed protesting students. Eleven of those students were treated by paramedics on scene and two were sent to a hospital in Sacramento for more intensive treatment.
Undoubtedly, these injuries will factor into another scientific study of pepper spray, another acknowledgement that top of the Scoville scale is dangerous territory. But my own preference is that we start learning from these mistakes without waiting another 13 years or more, without engaging in yet another cycle of abuse and injury.
As the article states, there seems to be disturbing pattern of law enforcement using Pepper Spray as torture —with out clinical trials, how can this be stopped?
This is the link to the Atlantic Monthly’s round-up of Pepper Spray use by law enforcement directed at OWS protestors.
Also, OOOG’s November 25th post, The Psychology of Pepper Spray describes two studies from the Netherlands on the efficacy of it’s use.