Characterizing Stimulant Overdose: A qualitative study on perceptions and experiences of “overamping”

Abstract

Background:

The dominant focus of North America’s current overdose crisis has been opioids, resulting in considerable research and harm reduction efforts to address opioid-related overdose risks. Less attention has been paid to people who use stimulants (PWUS) despite recent increases in stimulant use and stimulant-involved overdoses (i.e., “overamping”). Stimulant users’ definitions, risk factors and experiences of, and responses to, overamping are poorly understood, thereby putting PWUS at heightened risk of adverse health outcomes. This study explores how PWUS understand, experience, and respond to overamping.

Methods:

In-depth qualitative interviews were conducted with 61 PWUS in Vancouver, Canada’s Downtown Eastside neighbourhood. Thematic analysis of interviews focused on contextualizing stimulant overdoses, including how PWUS understand, define, experience, and respond to overamping.

Results:

Participants associated overamping experiences with commonly identified signs and symptoms, such as rapid onset, elevated heart rate, incontinence, and audio-visual hallucinations, but also reported more serious indicators of overamping, such as unconsciousness, cardiac arrests and seizures. Our findings demonstrate that, among PWUS, there was no unified understanding of overamping such as with opioid overdose and individual experiences had substantial variation in severity and presentation. This impacted the ability to adequately respond to stimulant overdoses, which were primarily self-managed through methods including stabilizing breathing, polysubstance use, and cold showers.

Conclusion:

Given the growing role of stimulants in North America’s overdose crisis, there is an urgent need to improve the identification of stimulant overdoses in real world settings. Our findings identify a gap in current understandings of stimulant overdose, and demonstrate the need for public health and harm reduction interventions to better address overamp risk among PWUS, including harm reduction campaigns to disseminate information regarding identifying signs of, and proper responses to, overamping.

Introduction

Illicit stimulant use has been steadily increasing globally, with North America having among the highest prevalence (Ruhm, 2019; United Nations Office on Drugs & Crime, 2019). This is attributed in part to the increase in the global supply of stimulants, majority of which is being produced in North America (United Nations Office on Drugs & Crime, 2019). In recent years, there has been a notable shift towards methamphetamine use and away from cocaine use in much of Canada and the United States (US) (Hedegaard, Bastian, Trinidad, Spencer, & Warner, 2018; Kariisa, Scholl, Wilson, Seth, & Hoots, 2019; United Nations Office on Drugs & Crime, 2019). This shift has not been uniform across the US, with regional trends suggesting that methamphetamine use and methamphetamine-involved overdose is more prevalent on the West Coast and cocaine use and cocaine-involved overdose is more prevalent on the East Coast (Ahmad et al., 2021; Centers for Disease Control and Prevention, 2021; Drug Enforcement Administration, 2019; Hoots, Vivolo-Kantor, & Seth, 2020). Recent research suggests that methamphetamine use has become more prevalent among several key subpopulations – treatment seeking populations, those who use other classes of drugs, and long-term opioid users (Ellis, Kasper, & Cicero, 2018; Lopez et al., 2021; Palamar, Han, & Keyes, 2020). The preference for methamphetamine use has been attributed to the longer half-life, increased accessibility (due to manufacturing processes and shifting drug supplies), lower cost, and higher purity (often above 90%) of methamphetamine compared to cocaine (Drug Enforcement Administration, 2019; Ellis et al., 2018; Visconti, Sell, & Greenblatt, 2019). Further, evidence suggests that in jurisdictions facing shortages of both prescription and illicit opioids, methamphetamine is often sought as an alternative and can serve as an adjunct for ongoing opioid use, assisting opioid withdrawal management and instrumentally being used to increase energy and functionality. (Ellis et al., 2018; Lopez et al., 2021).

Increasing rates of stimulant use are particularly concerning given the parallel increase in stimulant-involved overdose deaths (Drug Enforcement Administration, 2019; Hedegaard et al., 2018; Hoots et al., 2020; Kariisa et al., 2019; Ruhm, 2019; United Nations Office on Drugs & Crime, 2019). In the US from 2013 to 2019, the fentanyl-involved death rate increased by 1,040%, followed by the methamphetamine-involved overdose death rate which increased by 317% and the cocaine-involved overdose death rate which increased by 206% (Mattson et al., 2021). Meanwhile heroin-involved overdose deaths increased by 63% and prescription opioid-involved deaths remained stable during that time. While the rate of overdose deaths with co-involvement of fentanyl increased for all drug classes from 2013 to 2019 in the US (Mattson et al., 2021), amphetamine-involved deaths are more often occurring independently of concurrent opioid use (Kariisa et al., 2019). Recent data has also shown that, while psychostimulant-involved deaths have historically been concentrated in Western US, there have been dramatic increases across the country (Ahmad et al., 2021; Cano & Huang, 2021; Jalal et al., 2018). Notably, at a state-level these increases are positively associated with the severity of the opioid crisis, suggesting that an invisible epidemic of stimulant-related harm is well underway alongside the more well-publicized opioid overdose crisis (Cano & Huang, 2021; Ellis et al., 2018). Preliminary analyses of overdose data during early 2020 and the first several months of the COVID-19 pandemic suggest that overdose deaths involving cocaine or methamphetamine were already increasing prior to the pandemic and have continued to climb (Centers for Disease Control and Prevention, 2020).

Similar trends have been observed in Canada. In British Columbia (BC), Canada, methamphetamine-involved overdose deaths increased from 14% in 2012 to 43% in 2020 (BC Coroners Service, 2021). While cocaine-involved deaths have been steadily declining within that same timespan, cocaine nonetheless was implicated in 47% of the illicit drug toxicity deaths in 2020 (BC Coroners Service, 2021). For reference, fentanyl-involved overdose deaths rose from 5% in 2012 to 84% in 2020. While methamphetamine and cocaine have similar psychostimulant effects, studies have shown that both drugs have distinct patterns of subjective and cardiovascular response to acute administration which results in different half-lives (approximately 11 hours for methamphetamine and 90 minutes for cocaine) (Newton, De La Garza, Kalechstein, & Nestor, 2005). These engender distinct use patterns for people who use methamphetamine and cocaine, with the former characterized as using episodically throughout the day and the latter using more intermittently and prone to binge use (Simon et al., 2002). Binge use significantly increases the likelihood of overdoses and adverse health effects, especially if used in conjunction with other classes of substances (Fairbairn et al., 2008). Even as overdoses involving both stimulants and opioids remain common, the rapid increase of overdose deaths involving stimulants alone represents an urgent public health concern and yet little is known about how stimulant overdoses are experienced by people who use stimulants (PWUS).

In both the US and Canada, racial disparities in stimulant-involved overdose deaths persist and disproportionately high rates have been documented among communities of colour (Cano, 2020, 2021; Drake, Charles, Bourgeois, Daniel, & Kwende, 2020; Han et al., 2021). Recent data suggest that, while methamphetamine-involved overdose death rates increased for all racial and ethnic groups from 2011 to 2018, rates have remained highest and increased most dramatically among Indigenous communities (Cano, 2021; Han et al., 2021). Cocaine-involved overdose death rates remained high and more than doubled among Black communities in the US between 1999 and 2017 (Drake et al., 2020). Although overdose death rates among Latinx communities in the US have typically been lower than other major ethnic groups, rates have significantly increased since 2014 and 26.8% of Latinx overdose deaths in 2017 involved cocaine and 21% involved methamphetamine (Cano, 2020). Similar Canadian data is limited due to the lack of disaggregated data on Indigenous peoples however while First Nations constitute just 3.4% of BC’s population (First Nations Health Authority, 2017), Indigenous peoples accounted for 12.8% of overdose deaths in 2018 (First Nations Health Authority, 2019). The disparity between fatal overdose deaths between First Nations and non-First Nations women was especially alarming, with 39% of those deaths being that of First Nations and 17% of non-First Nations, revealing the over-representation of Indigenous peoples in the overdose statistics (First Nations Health Authority, 2019). Furthermore, the severity of the impacts of the overdose crisis is likely understated due to the lack of data collated on the various First Nations communities (Lavalley, Kastor, Valleriani, & McNeil, 2018).

While no single agreed upon definition of overamping exists, past studies have defined overamping using a variety of symptoms including, catatonia or an extended state of anxiety (Logan, 1996; Rotheram-Borus, Luna, Marotta, & Kelly, 1994) and some have limited this term’s application to methamphetamine overdose (Cox & Smart, 1972; Logan, 1996; McMahan et al., 2020). In consideration of this literature and local drug terminology, in this paper, the term “overamp” refers to an acute adverse event related to a high dose of stimulant use relative to an individual’s tolerance. Current overdose prevention strategies are primarily focused upon preventing opioid overdose, thereby failing to capture a significant portion of people using stimulants either alone or in combination with opioids. Opioid and stimulant overdoses have distinct physiological profiles and behavioural manifestations, with unresponsiveness, hypoxia, and reduced respiratory effort characterizing the former, and agitation, increased heart rate and body temperature, and/or cardiac arrest characterizing the latter (Lappin, Darke, & Farrell, 2017; Mayer et al., 2018; Oderda, Gan, Johnson, & Robinson, 2013; Stankowski, Kloner, & Rezkalla, 2015). This puts PWUS at high risk, as overamping produces a unique set of physical complications that cannot be reversed with naloxone.

In this qualitative study we seek to better understand stimulant overdose to inform harm reduction and policy initiatives for PWUS. Our study will also add to the rich body of qualitative literature that has helped expand our knowledge of, and response to, drug overdose (although it has primarily focused on opioids). Past qualitative research on opioid overdose and response strategies has contributed to refining service delivery and providing future policy directives. In the Canadian context, for example, qualitative scholarship has drawn attention to not only the benefits of safe injection facilities (SIFs) in safeguarding people who use opioids from fatal overdoses, but also the micro-contextual factors that shape injecting behavior and overdose risk in the absence of SIFs (Kerr, Small, Moore, & Wood, 2007). Additionally, rapid ethnographic fieldwork has extended current understandings of opioid overdoses by characterizing atypical opioid overdose presentations associated with fentanyl, emphasizing the need for responsive information sharing of these overdoses in order to support first responders and people who use opioids in overdose prevention efforts (Mayer et al., 2018).

Given the increase in stimulant-involved overdose and mortality, and the unique physiological characteristics of stimulant overdose, it is critical to better understand “overamping” as they occur in real world contexts to further understandings of how to identify and intervene in order to prevent morbidity and mortality of PWUS. While there is a significant amount of biomedical literature highlighting the physiological mechanisms underlying stimulant overdose, little is known about the lived accounts of stimulant overdose from the perspective of PWUS. Our study fills this gap by presenting firsthand accounts of overamping knowledge and experience, to broaden our understanding of overdosing on stimulants.

Methods

This study draws on semi-structured qualitative interviews conducted as part of a larger study exploring the experiences of, and responses to, stimulant use in Vancouver, BC. Eligibility criteria for this larger study consisted of being a current user of illicit stimulants (i.e., powder or crack cocaine, crystal methamphetamine). Study participants were recruited: (a) through community outreach by peer research assistants – team members with lived experience with substance use and trained in research methods as well as from ongoing cohort studies; and (b) through a linkage with the At-Risk Youth Study (ARYS) and Vancouver Drug Users Study (V-DUS). These prospective cohort studies include drug-using street-involved youth (ARYS; 14–24 years of age and past month use of illicit drugs at enrollment) and adults who use drugs (V-DUS; (≥18 years of age and past month injection drug use at enrollment) and involve bi-annual data collection (see: Tyndall et al., 2003; Wood, Stoltz, Montaner, & Kerr, 2006). Cohort participants were eligible to participate in this study if they reported current stimulant use (past 30 days) during their most recent follow-up survey interview. Prospective participants in both these cohorts were identified by the respective staff members of each cohort study and scheduled in to interview for the present study. Recruitment efforts by peer research assistants recruited people who self-reported frequently using illicit stimulants (methamphetamine, cocaine, crack cocaine) and considered them as their drug of choice. The majority of participants recruited through outreach and the cohort linkage were street-involved.

Semi-structured qualitative interviews were conducted with 86 PWUS between January 2019 and March 2020. All participants provided written informed consent and received $30 (CAD) honoraria for their involvement. Interviews were conducted by the lead and co-authors at two field research offices in Vancouver’s Downtown Eastside (adults) and Downtown South (youth). The Downtown Eastside neighbourhood is an area characterized by high prevalence of drug use, an open drug market, homelessness and unstable housing. An interview guide was developed by drawing on our team’s previous research, literature reviews, and input from people who use drugs. This guide was used to facilitate interviews and covered a range of topics, including but not limited to drug use history and current drug use, perceptions and experiences of overdose risk, and treatment experiences. Narratives around overamping experiences were probed with questions such as “When it comes to stimulants, what do words like “overdose” and “overamp” mean to you?” and “Can you tell me about what happened during your most recent stimulant-related overdose/ramp?” Interviews lasted on average 45–60 minutes, were audio-recorded, transcribed verbatim by a professional transcription service, and checked for accuracy.

In this paper we draw on a sub-sample of interviews with 61 participants, 27 of whom reported experiencing overamping and the remaining 34 participants had witnessed someone overamping and/or discussed their perspectives regarding overamping. Additionally, 11 of these 61 participants had used stimulants exclusively within the 30 days prior to their interview while the remaining participants reported using a range of substances over the same time span. We imported data into NVivo 12, a qualitative data management and analysis software program. We used a collaborative approach in developing the coding framework whereby all authors individually reviewed a portion of select transcripts and then identified common themes and categories such as overdose risk and experience, risk management strategies and drug practices. The coding framework was revised over the course of additional team meetings to refine the analysis as new themes and categories emerged. Furthermore, transcripts were doubly coded to ensure interrater reliability. Data were analyzed using thematic analysis for this paper and focused on narratives around knowledge and experience of stimulant overdose/overamp (Bernard, 2017). Pseudonyms were assigned to all participants using a random name generator. Ethical approval was obtained through the University of British Columbia/Providence Health Care Research Ethics Boards.

Results

Knowledge of overamping, overdose and terminology

Our sample predominantly comprised of people who lived in the Downtown Eastside neighbourhood. Most study participants had not heard of the term “overamp” prior to being interviewed, although nearly all could recognize the symptoms of stimulant overdose. Alternate terms such as “doing the chicken,” “beamed,” or simply “overdosed” were used by participants to describe overamping. Some participants did not consider the term overamp as referring to an overdose per se, but instead understood it as an extended period of sleep deprivation coupled with heavy methamphetamine use. Other participants did not recognize their overamping symptoms as that of an overdose as they believed that it was not possible to overdose on stimulants. When asked if she had experienced an overamp before, ‘Brooke,’ a 48-year-old white woman without prior overamp experience, expressed a common belief among our participants that overamp symptoms were an expected part of cocaine use:

P: No, I don’t know what even overamping is. I could see it, maybe.

I: …When your heart starts pounding real fast.

P: Well, that’s just due to cocaine. Welcome to world… If it [her heart] stops one day, well, hey.

Approximately half had direct experience with stimulant overdose, however participants often did not consider themselves to have experienced overamping until some of the characteristic symptoms were described by the interviewers. Rather, many participants did not consider their experiences as overdoses due to more commonly associating the term “overdose” with opioid-specific overdose presentations, specifically loss of consciousness. Several participants felt that overamping was not a primary concern when using stimulants in light of the wider concerns of fentanyl adulteration in the street drug supply. As ‘Kennedy’ (24-year-old, overamp-inexperienced, white woman, primarily methamphetamine user) explained when asked if people using methamphetamine were at a risk for an opioid overdose:

A little bit. But it’s definitely different playing field with that. Like you got to worry a lot more when you’re using heroin obviously but like there is… there is a lot of concern for that too… like I know, I know a lot of people who do down [heroin and/or fentanyl] and do check their drugs, like on a regular, but I don’t know anybody who does meth who checks their drugs. Like anybody. So that’s a big issue. You have no fucking idea. That’s why I think there’s only a concern. Like it’s not a big chance that something’s going to happen I think, it’s just we fucking we don’t know and nobody really is careful about it with that.

While stimulants were considered a safer alternative compared to street opioids in terms of safeguarding against an adulterated supply, the potential risks of a purely stimulant overdose were not a pertinent concern for most participants. Furthermore, as illustrated by Brooke, the symptoms characteristic of stimulant overdoses had been normalized among PWUS such that they were not regarded as a health concern, highlighting the extent to which public health efforts may have unintentionally sidelined the needs of PWUS while attempting to safeguard the wider drug-using community against the harms of fentanyl adulteration.

Identifying drivers of overamping

In contrast to opioid overdoses, which are largely driven by the fentanyl-adulterated drug supply (Mattson et al., 2021), stimulant overdoses were mainly attributed to overuse or binge use, stimulant potency, and polysubstance use. Among participants who had experienced or witnessed overamping firsthand, a predominant view was that overuse relative to one’s tolerance led to stimulant overamping. As described by ‘Alex,’ a 54-year-old white man whose drug of choice is heroin, when he accidentally injected a larger amount of cocaine than intended:

I did a frigging big whack of coke in 2016. It was too much. I was trying to get it out of the frigging rig… but it was in there like concrete eh, and I just finally goes fuck it and I frigging did it and my fucking body, and I says and whatever happens don’t fucking call 911 or nothing, but yeah, I fucked up and everything just got really, really fucking quiet eh, and fucking it started, and I just fucking went in convulsions for like 20 minutes. I couldn’t fucking stop. It was crazy.

In some instances, overamping was reportedly the result of a binge pattern of use as opposed to using “too much” in a single dose. ‘Keyla,’ a 25-year-old Latinx woman, recounted of her incident overamping after snorting cocaine: “I think I just used too much, maybe…I’m one of those people that I, once I have some, like I just keep going… It gets very hard to stop myself.”

The variability in potency of the unregulated illicit stimulant supply drove participants to use larger amounts of stimulants, potentially increasing their risk of overamping. While participants generally believed stimulants to be less adulterated than the illicit opioid supply, many expressed that the purity of stimulants available in Vancouver had been declining. Therefore, participants resorted to using larger quantities to achieve the same high that previously potent stimulants used to bring. When asked to describe the quality of cocaine over the years, ‘Aaron,’ a 63-year-old white man who primarily used cocaine, explained that earlier in his life it was “too strong” but that it was now “garbage [i.e., low quality].” He explained that PWUS were now using larger amounts. which he believed could cause an overdose: “People say to me, ‘right, oh, I done it for years, man. Like I always do a quarter [1/4 gram; a large amount].’’ I said nobody does a quarter without doing the chicken [overamping].” However, there were times when stimulants turned out to be more potent than participants were accustomed to, and this inconsistency presented an additional overdose risk factor. For example, ‘Carter,’ (47-year-old, Indigenous man, primarily methamphetamine user) reported experiencing symptoms characteristic of overamping in response to methamphetamine that was too strong relative to his tolerance level:

Back east I did some jib [meth] that was really strong and you could see my heart go through my t-shirt like this. It was pretty harsh. Be all sweaty hot and not even doing anything and I’m just looking at my heart and I’m like oh my god.

Participants commonly reported experiencing, witnessing, or hearing anecdotes of others experiencing symptoms of overamping with polysubstance use. The concurrent use of stimulants with other stimulants, opioids and/or other classes of drugs (e.g., psychedelics) were believed to have direct implications for their overamping outcomes. As ‘Serena’ (47-year-old, Black woman, primarily using cocaine) explained:

Crack and speed [methamphetamine] together. It felt like chest pain and I collapsed. My ex saved my life…I had a heart attack and they took me to the hospital.

Experiences of overamping

Participants frequently described the symptoms of overamping as a significantly high heart rate, excessive sweating, as well as difficulty breathing coupled with feelings of paranoia and anxiety. These experiences occurred across different routes of administration (e.g., injecting, smoking) and were commonly described as the defining features of the onset of an overamp and as remaining throughout the course of the experience. For example, ‘Kelly,’ (48-year-old, white woman, primarily using cocaine) described her experience:

I just started dripping profusely and I’m like yeah, wet, and you’re wet. I’m like dying, my mouth’s like so dry and I’m just dripping, like really there’s a pool on my forehead and I’m all red and just hot and it’s not from the heat, it’s from overdoing drug[s]… And [you] won’t stop sweating, even if you have a quick shower, you’re sweating again.

Those with firsthand experience of an overamp emphasized the rapid onset of symptoms. These symptoms were markedly distinct from the usual effects of the drug and were described as “overwhelming,” often occurring quickly and unexpectedly. As described by Keyla: “… just suddenly I realized and I’m like, ‘Oh, okay. It’s [overamp] happening.’ …Yeah, I don’t really feel it [overamp] coming”. Similarly, ‘Elena,’ a 43-year-old Indigenous woman whose drug of choice is cocaine, elaborated:

I jug, that’s where I shoot up in my neck, and I just, all I remember is fixing [injecting], closing the mirror, lighting [a] cigarette and waking up on the ground. Apparently, I did really violent shaking…

Reported symptoms included profound restlessness and a need to move around to offset these symptoms. ‘Val,’ a 61-year-old white man who primarily used methamphetamine, described the excessive energy he has experienced when injecting more of a goofball (i.e., heroin/fentanyl used in conjunction with methamphetamine) than he normally would:

All of a sudden, I’d be like, I can’t breathe, and I’ll get a paper bag or something, and a couple of times it’s gotten to the point where I was so high, I started getting paranoid and I’d open the door and I’d go out the door, down the hall, down the stairs, out onto the street, run around the block once, run around the block twice and come back home. Just because I was too high. I felt claustrophobia and I just had to get some air.

While Val’s symptoms aligned with those characteristic of stimulant overdose, he associated his experience with being “too high” rather than overdose, further underscoring the normalization of overamping symptoms, and suggesting that a certain symptom severity (e.g., loss of consciousness, seizures) must be achieved to be considered an overdose.

Other participants expressed difficulties with verbal communication and motor coordination, as well as incontinence, dissociation and/or visual hallucinations for the duration of the overamp. In contrast with Val’s experience, these presentations were viewed as far more unusual, and thus framed as more serious. ‘Lola’ (22-year-old, Indigenous woman, primarily using methamphetamine) highlights this while explaining her overamp experience:

I felt all numb, I couldn’t feel, like, my fingers went, like, this, and, like, couldn’t, like, crunch or anything…or too much, they were flinging back out…Yeah. And then this side…my right eye wouldn’t stop twitching non-stop. I was getting, like, heat waves after heat wave, and then all of a sudden, I’d get chills, and I was shaking back and forth, front to side and all that stuff. I couldn’t talk. I tried talking, but, like, my words just wouldn’t come out and he’s [her partner] just sitting there on his phone, and I’m, like, trying to get his attention, so, like, staggering to the bathroom because I couldn’t even walk, that’s how bad it was and it scared me…I’d try and get water, like, try and cup it on me but I’d get it all over the floor instead. It lasted for a good three hours.

Participants contrasted opioid overdoses with experiences of stimulant overamping and noted that in opioid overdoses “people just nod off. They then have to get Narcaned, more than once, I guess… Stimulant overdose, people shake. They have seizures. It’s more of like a physical, where you can see it.” (Kaya, 22-year-old white woman with prior overamp experience, primarily using crack cocaine). The majority of the participants who had experienced overamping emphasized doing the “funky chicken” - a term use to refer to stimulant-related tonic-clonic seizures.

Unconsciousness and/or memory lapses reportedly occurred either in conjunction with seizures or in isolation, but were not a consistent feature across all participant accounts of overamping. Similarly, reports of heart attacks and sudden cardiac arrests were experienced or witnessed by only a few participants. However, the severity of stimulant-induced heart attacks could result in fatal outcomes, as witnessed by a participant. While the medical literature indicates that stimulant use represents a significant cardiac risk factor contributing to heart attacks or cardiac arrests (Turner et al., 2018), the reported incidence of either was low in our sample, highlighting the wide range of symptom presentations that constitute overamping and that heart attacks and cardiac arrests simply represent the most extreme end on a spectrum of possible overamp presentations.

Responses to overamping

The novelty of overamping, due to the variable physical manifestations that rendered each experience as unique and challenges associated with recognizing and knowing the appropriate response to an overamp, complicated the management of the overdose. Most participants reported self-managing overamping due to the unique presentation and rapid onset, as well as the lack of awareness that they were in the midst of an overdose experience. Such strategies were often learned anecdotally from other PWUS and included administering other substances (e.g., cannabis, benzodiazepines, opioids) believed to counteract the overamp, cold showers, running around, or using paper bags or breathing techniques to modulate their heart rate. However, the lack of formally established overamp response strategies or medical interventions (e.g., naloxone) contributed to a shared understanding that the best practice for managing an overamp was to “ride it out”. ‘Jordan,’ a 23-year-old white man who had experienced overamps after snorting cocaine, explained that despite reports of various ways to counteract the effects of overconsumption, in his experience there were no actions or substances that could effectively stop an overamp:

Nothing is going to help you. You just have to sit there. It’s torture… honestly, that bullshit where you pat their back, or you talk them down, that does not work. They’re going to sit there like that no matter, because it has nothing to do with their mind. They’re fucked right now. They have so much shit in their nose, you’ve got to figure out how to make sure that that goes away faster… a lot of people, when you do mushrooms and so you want to cool down the high, you get orange juice. And it’s the same thing with cocaine. But the difference is, you can’t fucking just calm that down if it’s still in your body, right?

However, a number of participants, both with and without firsthand experience of overamping, attested to the use of relaxation techniques to manage symptoms, perhaps due to the perceived similarities between an overamp and a panic attack. Examples include encouraging breath modulation to manage hyperventilation and increased heart rate and reducing sensory stimulation. Others discussed using sunglasses to block out lights, speaking in calm, lowered tones, or simply trying to talk through the experience – strategies that attempt to reduce the physiological stress of an overamp, and acknowledge that while it cannot be reversed, it may be managed. For example, when asked how he dealt with overamping, ‘Lindsey,’ a 23-year-old Southeast Asian man with prior overamp experience who used cocaine, stated: “Chill. That’s the best thing you can do.” Conversely, other participants felt that pacing, running, or engaging in some form of movement helped mitigate overamping effects. In describing her firsthand experience managing an overamp, ‘Athena,’ (33-year-old, Indigenous woman, primarily using goofballs) who also tried to counteract an overamp with a sedative, explained:

I take a benzo, and then I just kind of wait it out a little bit, right? But I have to like pace, and like kind of be moving and stuff like that, for like half an hour. And it’ll eventually go away, but it’s scary, right?

She continued and highlighted the perception that overamps can be self-managed as – if not more – effectively than in hospital settings:

…Sometimes I wonder if I should go to the hospital, right? Because my heart is really racing, really fast. But I never go to the hospital. I think people should go to the hospital, maybe. Maybe there’s something that they can do…But I don’t know. I usually just wait it out.

Another overdose response strategy, primarily used by participants without firsthand overamping experiences, was cold showers. This was perceived as a reasonable response due to excessive sweating symptoms, and the need to “shock” the body. However, there were conflicting understandings of the safety of using cold showers as a response strategy, with some swearing by them and others explaining “you can actually shock someone that way… if you shove someone into a shower you can actually kill them” (‘Jay,’ 27-year-old Indigenous non-binary person with firsthand overamp experience while injecting methamphetamine). Those who had experienced overamping had developed specific methods of counteracting the negative effects of a stimulant overdose. For example, participants often used cannabis, benzodiazepines, or opioids to counteract overamping symptoms. Several participants attested to the effects of cannabis, explaining how it “just takes [the overstimulation] down a whole notch” (Keyla). Similarly, ‘Florence’ (62-year-old Indigenous woman, primarily using cocaine and heroin) described her suggestion on how to respond to overamps with opioids or benzodiazepines, which she based on her own prior experiences:

I just tell them to run or do you have any Valium, Valium or take a shot a bit of down [heroin], if you have any down, take a shot of that, that would bring you, calm you down… Anything that kind of, you know, calms your system down

Notably, very few respondents with firsthand overamp experience felt that medical attention was necessary, explaining that self-management of their overamping symptoms was an adequate strategy in avoiding any critical consequences. According to ‘Kaya, (22-year-old white woman, primarily using crack cocaine) who had overamped several times while smoking, most experiences were mild enough that “it’s nothing that really needs medical attention, really…I mean, unless someone has like a full-blown seizure. Then they need to go to the hospital.” However, the few that did choose to seek medical intervention credited it with saving their lives as they experienced life-threatening overamps involving heart attacks and/or seizures. Further, when responding to an overamp, respondents without firsthand experience resorted to calling paramedics. For ‘Cruz,’ a 23-year-old white man who had overamped once in the past year, he believed his lack of experience and knowledge of navigating a stimulant overdose would necessitate medical attention if he was ever to respond to one:

If they were capable of walking with me, I’d bring them to 7–11 or something, but if they weren’t, I would take the initiative and call an ambulance, because as soon as I see foam, you’re fucking get called. Fuck that shit. I’m not getting blamed for this shit… Because they have more information and experience and obviously, they’ve been firsthand with it. So even if that person that comes as the emergency technician and they’ve been high and shit, they know what to do too.

For Cruz, Kaya, and others, it was only once a certain threshold of symptom severity (i.e., heart attack, cardiac arrest, seizure) had been reached that they would consider medical intervention.

Discussion

Our findings demonstrate that overamping is common, but not well understood among PWUS. This was highlighted by a general lack of knowledge about stimulant overdose, a wide variety of experiences that constituted overamping, and a lack of formally established overamp response techniques and measures. While many participants had indeed experienced or witnessed overamps, they did not immediately attribute these experiences to stimulant overdose. Rather, it was often suggested these were simply expected reactions to using (or overusing) stimulants. This misunderstanding of overamp is especially concerning within the context of the ongoing overdose crisis in North America, and the increase in stimulant-involved overdoses (Hedegaard et al., 2018; Hoots et al., 2020; Kariisa et al., 2019; Ruhm, 2019).

Participant narratives revealed variable knowledge of what constitutes an overamp, and many did not know or think that stimulant overdoses were possible. Aligned with previous research (Fast, Kerr, Wood, & Small, 2014; Noroozi, Malekinejad, & Rahimi-Movaghar, 2018), participants in our study generally believed that stimulants were the safer alternative to opioids in terms of risk of adulteration. However, overamping presents substantial risk to PWUS as demonstrated by our study findings, and further supported by medical understandings of the potential physiological harms of overamping (Darke, Kaye, McKetin, & Duflou, 2008; Ho, Josephson, Lee, & Smith, 2009; Stankowski et al., 2015). The lack of evidence-based guidance on overamp reversal, within the context of a scale-up of opioid overdose reversal measures, has created an impression among many PWUD that such a risk does not exist for them. This underestimation of risk has been an unintended consequence that has far-reaching implications on participant willingness to seek medical attention for an adverse experience on stimulants if it did not reach a certain degree of symptom severity. This study draws attention to the divergence in participant perceptions of risk between these two classes of drugs and highlights future directions for harm reduction education which should focus on closing this gap in PWUS’ understandings of risk by presenting a comprehensive view of both opioid and stimulant overdose presentations.

Participants identified three key contexts in which overamps were experienced: overuse (relative to one’s tolerance), polysubstance use, and a potent supply. Stimulant use, and especially cocaine use is often characterized by binge use, which is associated with social and health problems (e.g., stimulant-induced psychosis, increased exposure to police, overdose risk), including increased risk of overamp (Segal & Kuczenski, 1997; Semple, Patterson, & Grant, 2003). Overuse can also be understood in the context of long-term exposure heightening risk of overamping. Studies have found that, while cocaine use does not necessarily need to be chronic to precipitate a cardiac event, long-term use is associated with increased cardiovascular damage that lead to stroke, aortic dissection, cardiomyopathy, and endocarditis (Cooper et al., 2013). This pattern of use, combined with the general lack of awareness of overamping risks among PWUS, highlights the need for widespread knowledge translation of overamp presentation and management strategies aimed at both frontline workers and PWUS.

Polysubstance use was often cited as a precipitating factor for overamping among many participants. The self-management of overamping caused by polysubstance use is complicated by the further use of multiple substances, highlighting a gap in participant understandings of the contributing factors to overamping and the appropriate response strategies in the event of a stimulant overdose. This is concerning given research on polysubstance use involving stimulants that has demonstrated substantial mortality and overdose risk accompanying this drug use practice (Geulayov et al., 2018; Kandel, Hu, Griesler, & Wall, 2017; Ruhm, 2017). This is a critical area to focus public health outreach efforts and develop and refine existent harm reduction measures. Our study supports the need for evidence-based overamp response measures, similar to the now well-established opioid overdose response strategies, including the need to offer PWUS access to safer alternatives to the illicit stimulant market, which would provide PWUS with confidence in the potency and source of their drugs (Fleming, Barker, Ivsins, Vakharia, & McNeil, 2020; Ruhm, 2017, 2019; Turner et al., 2018). Safer stimulant supply programs might also possibly have additional benefits, such as improved quality of life, similar to those reported in safer opioid supply programs (Ivsins et al., 2020). The majority of overamp-experienced participants reported overamping after injecting stimulants. This is aligned with previous research implicating injection stimulant use commonly in fatal and non-fatal cocaine overdoses, followed by inhalation and intranasal routes of administration (Pottieger, Tressell, Inciardi, & Rosales, 1992; Stankowski et al., 2015). Only two participants reported overamping after oral ingestion, which has implications for the design and delivery of safer stimulant supply programs to take into consideration non-oral use.

In characterizing the physical experience of overamping, our findings pertaining to a rapid heart rate, breathing complications, and potential for seizures and heart attacks highlight the degree of symptom severity recognized by participants and which is supported by research implicating the role of stimulants in cardiac and cerebrovascular risk (Huang et al., 2016; Lappin et al., 2017; Stankowski et al., 2015; Turner et al., 2018). Our study extends this research by demonstrating the variability in overamping presentations which complicates the accurate identification and response to overamps. Furthermore, key symptoms such as a rapid heart rate, breathing complications, and psychological symptoms such as restlessness and paranoia were considered by participants to be normal and inherently harmless responses to stimulant use by participants. However, previous research has shown that methamphetamine induces dose-dependent hyperthermia which has the potential to reach pathological levels (Miller & O’Callaghan, 2003). These findings can be used to further streamline and target existent harm reduction messaging towards the dispelling of common myths within the stimulant-using community. The unique presentation and rapid onset of symptoms led many participants to resort to self-managed interventions in order to alleviate overdose symptoms, through polysubstance use or the use of cold showers which could have mixed and sometimes harmful results.

Similarly, the psychological symptoms of overamping such as feelings of paranoia, anxiety and agitation were often self-managed by breathing techniques, pacing or running around, or reducing sensory stimulation. While the effect of the drugs themselves contributed to these symptoms, these feelings of anxiety and agitation can also be partially attributed to the novelty of these experiences, in that they have unique presentations, and participants’ lack of knowledge on how to alleviate them. With the creation and dissemination of harm reduction material that outlines the spectrum of overamp symptoms, participants can be better equipped in recognizing their experiences as stimulant overdoses. Additionally, educational material created in collaboration with PWUS and medical experts that provide descriptions of self-management techniques that could be utilized in the event of an overamp would promote self-efficacy and confidence in navigating themselves or others through overamping. Certain techniques identified by the participants in this study such as reducing sensory stimulation by dimming the lights or turning off music, modulating breathing, having a peer calm them and supervise them, and taking a walk or a jog should be included as potential response strategies for self-management of overamping. Further, participants frequently had conflicting understandings of the safety of response strategies (e.g., cold showers) and whether medical attention was necessary. The use of cold showers is also contentious and existent harm reduction messaging advises the use of cool wet cloth on areas such as the forehead and back of the neck instead. (Toward The Heart, 2021). Whereas most self-directed response strategies were relatively benign, attempting to offset an overamp with other substances, especially using benzodiazepines or opioids, complicates both overamp presentations and response and should be advised against (Geulayov et al., 2018; Hawton et al., 2010).

While underscoring the importance of equipping PWUS with the necessary knowledge for self-efficacious risk mitigation, the rapid onset, variability, and severity in overamping experiences point towards an urgent need for supervised consumption facilities that accommodate the needs of PWUS. The implementation and scale-up of supervised consumption services has been a focal area in BC’s response to the opioid-overdose crisis and has been highly effective in reducing opioid-overdose risk and mortality (Kennedy, Karamouzian, & Kerr, 2017; Marshall, Milloy, Wood, Montaner, & Kerr, 2011; McNeil & Small, 2014). However, these facilities do not meet the needs of stimulant users such as having space for drug inhalation, or measures designed specifically to address the psychological and behavioural symptoms such as built-in spaces with reduced sensory stimulation or peers and/or nurses that are acquainted with recognizing and responding to overamps (United Nations Office on Drugs and Crime, 2019). While severe cases of intoxication require the use of sedatives such as benzodiazepines to reduce distress, behavioural interventions can be used as the first-line treatment for acute symptoms such as anxiety, paranoia, and aggression. An added benefit of such spaces is the provision of safety during periods of intoxication, reduced inhibition and cognition. Furthermore, it safeguards PWUS from harms related to the criminalization of drug use, such as policing and incarceration, as well as exploitation from using in public or private settings, both of which perpetuate the marginalization of racial and sexual minorities in society.

This study has highlighted several gaps in the medical understandings and available harm reduction programming. The firsthand experiences and understandings of overamping that PWUS have shared in this study have expanded the previously limited scope of overdose symptomology and driving factors of overamping further emphasizing the need to keep PWUS with lived experiences of overamping at the forefront of the creation of educational and community initiatives in order to ensure their relevancy and applicability in real-world settings. In the absence of formal harm reduction education for stimulant use, PWUS have adapted ways of self-managing overamps – many of which have proven to be effective, highlighting the impact of community-driven knowledge and the need to integrate them into academic knowledge and knowledge translation efforts that may benefit the wider community of PWUS. The development and implementation of stimulant-specific overdose response measures is crucial to reduce overdose risk among PWUS, and to reduce disparities in harm reduction support within communities of people who use drugs (McNeil, Kerr, Lampkin, & Small, 2015). Having medical professionals and PWUS collaborate in the development of public health messaging surrounding overamping would serve to create consistency and relevancy in understandings of overamping across care providers and PWUS. Additionally, the lack of a standardized medical definition of overamping that delineates moderate and extreme overamp symptomology presents an important step that should be addressed in developing public health messaging surrounding this issue (Cox & Smart, 1972; Logan, 1996; McMahan et al., 2020).

A focus on opioid risk mitigation has been central to recent overdose response and harm reduction measures in much of North America through the scale-up of naloxone distribution, medications for opioid use disorder, and in some Canadian settings, supervised consumption sites and safer supply programs (Fairbairn, Coffin, & Walley, 2017; Ivsins et al., 2020). While these efforts are certainly warranted given the proliferation of fentanyl and related analogues in the illicit street-drug supply (BC Coroners Service, 2021; Mattson et al., 2021), these services do not address or acknowledge the distinct needs of PWUS. Our findings underscore the critical need to develop peer-led, evidence-based risk mitigation and overdose response strategies for PWUS, and to integrate these within overdose responses. Meaningfully involving peers in the development and implementation of community-based interventions has been shown to improve service engagement (Davidson, Lopez, & Kral, 2018; Karazivan et al., 2015). Additionally, collaboration between frontline peer support workers, overdose first responders and PWUS in knowledge translation activities regarding overamping would improve the stimulant overdose response.

This study has several limitations. Firstly, it was undertaken in the Downtown Eastside neighbourhood of Vancouver, a unique setting characterized by a significant open drug market and an increasingly unpredictable drug supply, and therefore our findings may not be generalizable to other settings. Further, given the variability of drug markets, and a rapidly-changing drug supply in the study setting, experiences of overamping described by our study participants may not be reflective of experiences of PWUS elsewhere. Additionally, our findings may be complicated by varying subjective understandings and experiences of overamp among the study participants, and as such do not allow us to present a succinct definition of overamping. regarding stimulant overdose and its very subjective understandings and experiences. Furthermore, previous studies have highlighted that despite general ranges of lethal dosage being established for various stimulants, there continues to be significant individual variability in toxicity thresholds (Gold, Miller, & Jonas, 1997; Mori, Suzuki, & Ishiyama, 1992). This data also has potential for survival bias as we were unable to capture the degree to which fatal overdoses can have different precipitating factors and presentations. Furthermore, while we discuss stimulant use as an umbrella term throughout the study, distinctions exist in overamp experiences and subsequent management strategies between different types of stimulants. While this level of specificity is beyond the scope of the current study, further work in collaboration with PWUS and medical experts is necessary to delineate these distinctions and refine educational tools.

Our study builds on existent quantitative and clinical literature on stimulant overdoses by offering first-hand perspectives on experiences, challenges, and management strategies of overamps among PWUS. Findings demonstrate that stimulant overamp and overamp-response strategies are not well understood, putting PWUS at heightened risk. Evidence-based response strategies that equip PWUS with the tools necessary to respond to overamps must be central to these efforts and need to communicated not only to PWUS as a whole but also to relevant first responders so that they are equipped to respond appropriately to overamping. Within the intersecting contexts of drug criminalization and the overdose crisis, the need to design and implement services that are relevant to PWUS, alongside the scaling up of current harm reduction measures (i.e., safe supply, supervised inhalation facilities), are of critical importance.

Table 1:

Participant Characteristics

Participant characteristics	n (%) N=61
Age
Mean	41 years
Range	21–65 years
Gender
Men	27 (44%)
Women	32 (53%)
Transgender, two-spirit, or non-binary	2 (3%)
Race
White	27 (44%)
Indigenous	27 (44%)
Other	7 (12%)
Substances used in past 30 days a
Cocaine	27 (44%)
Crack cocaine	26 (23%)
Crystal Methamphetamine	34 (56%)
Heroin	18 (30%)
Fentanyl	13 (21%)
Other substances	41 (67%)
Marijuana	37 (61%)

Table 2:

Overamp-experienced Participant Characteristics

Participant characteristics	n (%) N=27
Drug used during overamp a
Cocaine	9 (33%)
Crack cocaine	3 (11%)
Crystal Methamphetamine	10 (37%)
Heroin	2 (7%)
Fentanyl	5 (19%)
Other	4 (15%)
Method of drug administration during overamp b
Inject	13 (48%)
Inhale	3 (11%)
Snort	5 (19%)
Ingest (oral)	2 (7%)
Location during overamp b
Supervised consumption service	2 (7%)
In-suite (at home)	10 (37%)
In building	2 (7%)
Friend’s place	4 (15%)
Outside/Public	4 (15%)
Other	0 (0%)

^aParticipants could report multiple options

^bIncludes incomplete data

Highlights.

• Explores firsthand accounts of understandings, drivers, experiences of, and responses to overamping by people who use stimulants

• Experiences and understandings of overamping vary considerably

• Lack of awareness and knowledge of overamping lead to potentially harmful self-managed response strategies