Lifeless, listless, soulless: Zombies. Spoiler alert, they don’t exist. At least not in the mammalian world, although there are examples of zombie bugs and plants (Cohut, 2019). Yet the zombie lives on in our society’s collective consciousness through countless films, TV shows, and video games. Recently this term has gained popularity outside of fiction, in reference to the side effects of synthetic drugs including alpha-PVP, xylazine, and PCP. Media reports say highly alarming things about these drugs, including that these drugs have “made people kill”, that they cause “mad, violent, zombie-like rampages”, and that they “rewire brain chemistry” (Miller-Hoover, 2019). Is there truth to these claims? What do these so-called “zombie drugs” actually do? This post is an attempt at demystifying the so-called zombie drugs.

What are “Zombie Drugs”?

“Zombie-drugs” include synthetic cathinones (SCs), often used as substitutes or adulterants for methamphetamine or MDMA due to their low cost (de Moura et al., 2021). Synthetic cathinones, commonly referred to as “bath salts”, induce psychomotor stimulant and/or psychoactive effects which are mimetic of drugs such as cocaine, meth, or MDMA, but can be more potent (de Moura et al., 2021). Effects are believed to be mediated by their ability to block the reuptake or increase the release of monoamines including dopamine, norepinephrine and/or serotonin, although their properties are not yet fully understood (de Moura et al., 2021; Kuropka et al., 2023). Synthetic cathinones are often used recreationally to enhance mood and alertness (Baumann, 2014). One literature review by Patocka et al., (2020) explains that symptoms of psychosis and altered mental status can happen including delusion, and agitated delirium– which is excessive sympathetic nervous system activation that can result in dangerous symptoms such as anxiety, bizarre behavior, agitation, confusion, fast heart rate, high blood pressure, hyperthermia, sweating and dilated pupils (Patocka et al., 2020). SCs also have the potential to cause addictive behaviors including self administration in Rhesus monkeys (de Moura et al., 2021).

Synthetic cathinones are not the only so-called zombie drugs. More recently the label of zombie drug has shifted towards Xylazine or “tranq”. Xylazine was originally used as a veterinary tranquilizer not intended for human consumption. But is being used recreationally, mainly as an adulterant to opioids and cocaine (Mulders et al., 2016). It is a synthetic non-opiate sedative and analgesic, with vastly different symptoms than cathinones including hypothermia, respiratory depression and low heart rates among many others (Mulders et al., 2016). Xylazine is a “zombie drug” in reference to the severe wounds and necrosis which may happen at the site of injection (Mulders et al., 2016).

Why are they called zombie drugs?

1. Skin deterioration: Xylazine is commonly delivered through injection. Injections can cause skin lesions, including ulcers and lesions, related to skin hypo-oxygenation (Mulders et al., 2016). [Graphic images below for those who are curious about the appearance of Xylazine lesions]
2. Abnormal movement: synthetic cathinones act on the central nervous system, and are associated with atypical unfocused and frantic movement, including head weaving, circling, and muscle clenching (German et al., 2014).
3. Agitated delirium: In addition, people taking excessive doses may experience agitated delirium which presents with bodily symptoms, agitation, and confusion,

But perhaps, more memorable to the public…

Most importantly perhaps, media reports of cannibalism: The first major instance of the “zombie drug” was based on media sensation that one man, Rudy Eugene, had taken synthetic cathinones and had attacked Ronald Poppo by biting and “eating” half of his face (O’Malley & Medina-Kirchner, 2020; news report by Luscombe, 2012). Poppo was blinded in one eye and suffered major facial damage from the attack. Rudy Eugene was shot by police (Luscombe, 2012). The media quickly spread sensationalized reports of a “cannibal attack”. Toxicology reports ruled out the use of synthetic cathinones in his system, there was also no evidence of ingested human skin (O’Malley & Medina-Kirchner, 2020; Luscombe, 2012). This toxicology report does not entirely rule out the possibility that Eugene was on SCs, because there are chemical variants of bath salt-type SCs which may be unknown and therefore unable to be tested for (news report by Wolchover, 2012). Dr. Carl Hart, author of Drug Use for Grown Ups, described the sort of “cat-and-mouse game” relationship between criminalization and uncontrolled drug production (Hart, 2021), whereby when one synthetic drug is banned, drug producers introduce a slightly modified replacement to circumvent these laws, leading to the creation of unidentifiable, undetectable, and generally more potent SCs (Hart, 2021). But this report also can not confirm that he had taken SCs either.

In 2016, Martin County Sheriff William Snyder of Martin, FL had initially reported that “Flakka”, a synthetic cannabinoid, was involved in the double murder case of 19 year old Austin Harrouff (news report by Deluca, 2022). Austin Harrouff was said to have taken the SC “Flakka” before he murdered John Steven and Michelle Mishcon outside of their home (Deluca, 2022), He was found biting the face and abdomen of one of his victims. Toxicologists again found no toxicological evidence of the “zombie drug”. The parents of the murderer had reported that he had been experiencing strange behavior prior to the attack, which may have resulted from an undiagnosed mental illness (news report by Alonso, 2022). Harrouff was found not guilty to two counts of first degree murder by reason of insanity (Alonso, 2022).

I do not say these things in order to sympathize with the actions of murders. I say these things to remind readers that correlation is not causation, and to urge readers to be skeptical of news and scientific research reports. Synthetic cannabinoids do not cause someone to become a zombie. SCs also do not cause people to murder. SCs do affect the brain, which may cause abnormal psychological and behavioral symptoms, which may, or may not have had a role in the actions which Rudy Eugene and Austin Harroff committed. It is important to continue to be skeptical and think critically about the language which the media uses to portray drug users in order to have a less biased understanding of the story.

Works Cited

Alexandrescu, L. (2020). Streets of the ‘spice zombies’: Dependence and poverty stigma in times of austerity. Crime, Media, Culture: An International Journal, 16(1), 97–113. https://doi.org/10.1177/1741659019835274

Alonso, M. (2022, November 29). Suspect in 2016 double murder, face-biting case found not guilty by reason of insanity. CNN, Retrieved from https://www.cnn.com/2022/11/29/us/florida-killings-face-biting/index.html.

Baumann, M. H. (2014). Awash in a sea of ‘bath salts’: implications for biomedical research and public health. Addiction, 109(10), 1577–1579. https://doi.org/10.1111/add.12601

Cohut, M. (2019, October 31). What are the real zombies?. Medical News Today. Retrieved from https://www.medicalnewstoday.com/articles/326871.

Deluca, A. (2022, August 24). What you should know ahead of accuses “face-eating murderer” austin harrouff’s trial. Miami New Times. Retrieved from https://www.miaminewtimes.com/news/austin-harrouff-case-what-to-know-ahead-of-face-eating-murder-trial-14879652.

de Moura, F. B., Sherwood, A., Prisinzano, T. E., Paronis, C. A., Bergman, J., & Kohut, S. J. (2021). Reinforcing effects of synthetic cathinones in rhesus monkeys: Dose-response and behavioral economic analyses. Pharmacology Biochemistry and Behavior, 202, 173112. https://doi.org/10.1016/j.pbb.2021.173112

Hart, C. (2021). Drug use for grown ups. Penguin Press. New York, NY

German, C. L., Fleckenstein, A. E., & Hanson, G. R. (2014). Bath salts and synthetic cathinones: An emerging designer drug phenomenon. Life Sciences, 97(1), 2–8. https://doi.org/10.1016/j.lfs.2013.07.023

Luscombe, R. (2012, August 9). Miami face-chewing victim: attacker Rudy Eugene ‘ripped me to ribbons’. The Guardian. Retrieved from https://www.theguardian.com/world/2012/aug/09/miami-face-chewing-victim-attack.

Miller-Hoover, S. (2019). Flakka: the zombie drug [Blog post]. Retrieved from https://www.rn.com/headlines-in-health/flakka-zombie-drug/.

Mulders, P., van Duijnhoven, V., & Schellekens, A. (2016). Xylazine Dependence and Detoxification: A Case Report. Psychosomatics, 57(5), 529–533. https://doi.org/10.1016/j.psym.2016.05.001

O’Malley, K. Y., & Medina-Kirchner, C. (2020). MDPV-induced aggression in humans not established. International Journal of Legal Medicine, 134(1), 261–262. https://doi.org/10.1007/s00414-019-02165-3

Patocka, J., Zhao, B., Wu, W., Klimova, B., Valis, M., Nepovimova, E., & Kuca, K. (2020). Flakka: New Dangerous Synthetic Cathinone on the Drug Scene. International Journal of Molecular Sciences, 21(21), 8185. https://doi.org/10.3390/ijms21218185

Reyes, J. C., Negrón, J. L., Colón, H. M., Padilla, A. M., Millán, M. Y., Matos, T. D., & Robles, R. R. (2012). The Emerging of Xylazine as a New Drug of Abuse and its Health Consequences among Drug Users in Puerto Rico. Journal of Urban Health, 89(3), 519–526. https://doi.org/10.1007/s11524-011-9662-6

Wolchover, N. (2012, June 29). Marijuana didn’t trigger miami face-eater’s munchies. Live Science, Retrieved from https://www.livescience.com/21276-marijuana-bath-salts-cannibal-attack.html.