UNDERSTANDING CONCURRENT STIMULANT USE AMONG PEOPLE ON METHADONE: A QUALITATIVE STUDY

Abstract

Background:

Opioid-related overdoses are an epidemic in North America, prompting greater use of medications for opioid use disorder, such as methadone. Although many people work toward overall drug abstinence while on methadone, a sub-population of people with and without histories of polysubstance use engage in stimulant use while on methadone treatment. This study explores motivations for concurrent stimulant and methadone use in a street-involved drug-using population.

Methods:

Semi-structured qualitative interviews were conducted with 39 people on methadone in Vancouver, Canada. Participants were recruited from among participants in two community-based prospective cohort studies comprised of HIV-positive and HIV-negative people who use drugs. Interview transcripts were analyzed using an inductive and iterative approach.

Results:

Our analysis identified three primary themes. First, participants articulated how stimulants were used to counter the sedating effects of methadone and enable them to engage in daily and survival activities (e.g., income generation). Second, participants described increased stimulant use to compensate for reduced stimulant intoxication while taking methadone. Finally, participants described the desire to achieve intoxication on stimulants once stable on methadone, as their substance use treatment goals did not involve drug abstinence.

Discussion:

Among a street-involved drug-using population in which people do not have abstinence-based treatment goals, there are several functional reasons to use stimulants concurrently while on methadone. A deeper and more nuanced understanding of substance use motivators may contribute to further research and inform policy and guideline changes that support low threshold and harm reduction-focused methadone treatment programs and other interventions to reduce drug-related harms.

INTRODUCTION

North America is experiencing an overdose epidemic, with fentanyl-adulterated opioids driving dramatic increases in overdose related morbidity and mortality (1). As such, many jurisdictions are scaling up the provision of medications for the treatment of opioid use disorder, including methadone. Methadone has been shown to be more effective reducing drug-related harms than non-pharmacological outpatient treatment approaches (2), including reductions in overdose mortality (3) and the transmission of hepatitis C and HIV infection (4, 5). Enrollment in methadone has also been shown to reduce engagement in criminalized activities and promote HIV treatment initiation and adherence (6–8). Methadone represents a critical treatment approach for opioid use disorder, especially amidst the overdose epidemic, and there is limited understanding of the methadone experiences of people reporting polysubstance use – that is, the use of multiple substances such as opioids and stimulants (e.g., cocaine, crack cocaine, methamphetamine). We are only beginning to understand the complexities of methadone among polysubstance-using populations for which methadone may only address some of the substance use treatment needs, something that warrants attention as overdose deaths among polysubstance-using populations continue to rise in North America (9).

Despite considerable attention to methadone outcomes in abstinence-oriented treatment programs (2, 10, 11), fewer studies have been conducted to examine methadone treatment among polysubstance-using populations. Although some research has shown that methadone reduces both opioid and cocaine use (2, 10, 12–15), some individuals enrolled in methadone continue to use substances and may have treatment goals that differ from traditional abstinence-based outcomes (16, 17). Methadone has been found to be less effective in polysubstance-using individuals with regard to abstinence from illicit opioids (18). Although a few studies indicate that retention in methadone reduces cocaine use (14), especially among those reporting high levels of cocaine use, other studies suggest that stimulant use while on methadone leads to a poor response in terms of retention, abstinence from opioid use, and possibly a decreased pharmacokinetic effect of methadone (19). In addition, some evidence suggests that cocaine use among those on methadone may be associated with treatment discontinuation (20).

Qualitative research among structurally vulnerable polysubstance-using individuals from a variety of settings, including Vancouver, Canada, supports the notion that the acceptance of and adherence to methadone treatment is a much more complex situation than is reflected in clinical and epidemiological studies (17, 21). These studies have suggested that treatment goals of people who use drugs might not necessarily be abstinence from all substance use (16). Some methadone providers have responded to engage these populations by offering low threshold methadone treatment options, which are based on an explicit “rejection of abstinence from opioids and other drugs as the overarching treatment goal” (16). Those providing services within this paradigm hold that the goal of low-threshold methadone treatment is to reduce drug-related harms, such as overdose, syringe-sharing, HIV and HCV transmission, and injection-related injuries, as well as social harms (16, 22, 23). However, in many cases, stimulant use in the context of methadone treatment can lead to punitive measures, like involuntary treatment discontinuation, in settings operating under abstinence-oriented approaches, thereby underscoring the need for attention to this phenomenon. Moreover, as methadone and other medications (e.g., buprenorphine, etc.) are critical to addressing the overdose crisis, the need to better understand motivations behind ongoing substance use among those enrolled in methadone is important to optimizing treatment and its alignment with individuals’ priorities, as well as developing complementary harm reduction strategies to reduce the harms associated with ongoing drug use in the context of increasingly volatile illicit drug supplies. Such insight will be necessary to ensure that safe and comprehensive approaches (including low threshold methadone treatment programs) are aligned with individuals’ needs and address the contexts influencing their substance use and lives. Our study aims to add to this literature by exploring the reasons for stimulant use among people enrolled in methadone treatment, and understand treatment goals that do not necessarily include drug abstinence.

METHODS

We draw upon semi-structured qualitative interviews conducted with people on methadone who are part of a larger ethno-epidemiological study of experiences with substance use treatment programs in the Vancouver and Lower Mainland area of British Columbia, Canada. Prior to commencing this study, ethical approval was obtained from the University of British Columbia/Providence Health Care. Participants were recruited from two ongoing cohort studies operating in Vancouver’s Downtown Eastside neighborhood, which have been described in detail elsewhere (17, 24). These cohorts include more than 2000 people who use drugs -- the Vancouver Drug Users Study (VDUS, HIV-negative cohort) and AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS, HIV-positive cohort). In brief, cohort participants are recruited through community outreach and a research office. They complete structured questionnaires and clinical assessments at baseline and every six months thereafter (17).

Between February and July 2014, VIDUS and ACCESS cohort participants were recruited into this qualitative study if they reported enrollment in any kind of substance use treatment in the last 6 months as part of the first wave of data collection for the larger ongoing study. The first wave of data collection for this larger study prioritized the recruitment of people on methadone treatment. 39 of the 45 participants recruited into the larger ethno-epidemiological study during this study period reported lifetime exposure to methadone, and 34 were enrolled in methadone treatment at the time of their interview. For the purposes of this report, we draw upon interviews with these 39 participants, all of whom reported concurrent methadone and stimulant use at some point while enrolled in methadone treatment (see demographics in Table 1).

Table 1:

Participant Demographics

Participant characteristics	N=39
Age
Mean	46 years
Range	26 – 64 years
Gender
Men	22
Women	17
Race
White	28
Indigenous	10
Black	1
Health Status
HIV-positive	20
Drug Use (thirty days prior to interview) a
Heroin	26
Crack Cocaine	19
Cocaine (Injected)	13
Crystal methamphetamine	9
Polysubstance use (thirty days prior to interview)	24

The study was explained to eligible participants by cohort staff, and interviews were scheduled with those who were willing to participate. Nearly everyone approached about potential participation in a qualitative interview agreed to participate, although several cohort participants who agreed to participate after being invited did not show up for their scheduled qualitative interviews and could not be reached to reschedule.

Trained interviewers explained study procedures to participants and obtained written informed consent before conducting interviews. All interviews were conducted in the cohort study research office. In addition to lines of inquiry focusing on experiences with specific drug treatment programs, participants were asked to describe their dosing and access to methadone treatment, experiences of methadone initiation, and motivations and context for ongoing drug use. Participants were provided a $30 honorarium following their interviews. Interviews averaged 45 minutes in length, were audio recorded, and transcribed by externally-contracted professional transcriptionists. Interviewers met regularly during data collection and team meetings were also held to discuss and reflect on emerging findings, which helped to inform probes used during subsequent interviews. As instrumental uses of stimulants emerged as a key finding during early interviews, specific attention was paid to these dynamics throughout the study.

Interview transcripts were imported into NVivo, a qualitative data management and analysis software, to facilitate coding. Interview transcripts were coded using inductive and deductive methods. We used a preliminary coding framework comprised of a priori codes drawn from the interview guide and informed by interviewer and team discussions during data collection, and regularly revised it to accommodate new codes that emerged during the analysis (25). Study findings were presented to the British Columbia Association of People on Opioid Maintenance (BCAPOM), a peer-driven advocacy organization, to elicit feedback and enhance validity. Data excerpts presented in the Findings sections are representative of the views of our participants, and resonated with members when presented to BCAPOM.

RESULTS

Stimulant use counteracts unwanted methadone effects

Participants had enrolled in methadone treatment to manage the harms associated with opioid use within a criminalized environment, most notably regular experiences of opioid withdrawal (i.e., ‘dopesickness’). Most participants had achieved – at minimum, episodically – significant reductions in illicit opioid use while enrolled in methadone treatment, including both periods of abstinence from illicit opioids and reductions in the frequency of illicit opioid use. However, participants expressed that stimulants had some role in helping them to function in their daily lives while living with side effects of methadone treatment, particularly fatigue. Constraints imposed upon participants by their structural vulnerability, such as insufficient resources for transportation to the pharmacy or other appointments, unstable or unsafe housing situations in which theft or damage to property is common, or the occasional need to manage affairs with violent drug dealers in a criminalized market, require constant vigilance and energy. Additionally, participants engaged in informal and criminalized income generating activities (e.g., recycling, drug selling, sex work) highlighted the need to have enough energy to engage in these activities. Within this context, participants expressed that the use of stimulants was an enabling factor that allowed them to structure their lives, meet daily survival needs, and engage in income generating activities by mitigating the sedation and fatigue that was often experienced while taking methadone. For example:

I know I gotta go to appointments and stuff like that, I mean I gotta make sure…Like, yesterday I had go get my ultrasound done. Well, I made sure I had money for yesterday so, before I went there, I had my toke [of crack cocaine] to keep me awake. ‘Cause otherwise, if I didn’t have my toke, I’m gonna be fucking sleeping. You know, I’m not gonna wanna go and I’m just gonna be, you know, like, ‘Ahhh, whatever.’ I’ll plug my ears and not wanna go. You know, [I will] go to sleep again.

[Black Woman, 52 years old]

This participant later described the use of crack cocaine to mitigate the lack of energy associated with the onset of withdrawal symptoms, suggesting that her stimulant use was complex and possibly helped to provide energy when methadone was not fully addressing her opioid withdrawal management needs:

Only if I’m doing the rock then I don’t think about the heroin. I don’t get sick but, as soon as I stop smoking the rock, then I’m gonna get sick.”

[Black Woman, 52 years old]

Another participant described escalating stimulant use to combat fatigue and a perceived loss of energy experienced when initiating methadone:

I was doing a lot of cocaine and…then I was smoking crack. […] I was trying to compensate, I guess, for the loss of energy, you know.”

[Indigenous Woman, 55 Years Old]

Despite the common experience of methadone causing fatigue and sedation, some participants reported that they experienced minimal side effects with methadone and, therefore, these instrumental uses of stimulants were unnecessary for them.

Desire to continue stimulant use

Among participants, continued or increased use of stimulants was identified as necessary to achieve desired drug intoxication while taking methadone. Many participants had long histories of polysubstance use and wished to continue to occasionally or regularly use stimulants, while also achieving greater stability in relation to their opioid use though methadone. In some cases, methadone was perceived to impact the degree of stimulant intoxication, which led to the intensification of stimulant use for some participants. For example, one participant described how their increased use of cocaine stemmed from the fact that they were achieving a less satisfying cocaine high while on methadone:

Even though I’m off the heroin and I’m on the methadone, I don’t do rock [i.e., crack cocaine]. I used to do rock but I don’t do the rock. So now I’m doing the powder [cocaine]. But I find with the methadone, it’s a little harder. Like, I don’t get that high when I do my first fix. And, even throughout the day, I try to do, a little bit more than I usually do. But I still- It’s still- I can’t [achieve the desired high]. So more or less I’m just throwing money out the window.

[White Man, 51 years old]

Notably, this participant transitioned from smoking crack cocaine to injection use of powdered cocaine due to the perceived impacts of methadone on the high associated with stimulant use - indicating its potential to influencing stimulant use patterns (e.g., substance and route of administration).

Other participants described an increase in stimulant use once starting methadone, but did not necessarily correlate it with a lesser high. In some cases, these increases in drug use were situational or relational, and reflected ongoing drug use among their peers. For example, participants described changes in their stimulant use patterns when the composition of their social networks changes (e.g., entering into a new intimate partnership, reunited with a partner released from prison). Other participants reported using cocaine or crystal methamphetamine in combination with other non-opioids following initiation of methadone to achieve desired levels of intoxication no longer possible by mixing these drugs with opioids (e.g., mixtures of cocaine and heroin known as speedballs). For example:

I didn’t stop [using cocaine or heroin]. I was doing speedballs [mixed heroin and cocaine]… I was able to stop the heroin… [Interviewer: And then still using sometimes?] Benzos and cocaine.

[White Man, 53 years old]

New stimulant use due to methadone effects

It is important to note that some participants transitioned from opioid use to stimulant use following their initiation of methadone treatment. In these cases, participants reported that they were able to achieve their goal of effective cessation of opioid use while on methadone, but transitioned to stimulant use. For example:

It makes it harder to get off it [methadone], but it totally curbed [heroin use] – like there was no use in doing heroin once I was above 20 ml [of methadone] unless I felt like spending $100 on a shot, which is just stupid, so [laughter] yeah, it just wasn’t worth it…That just directed me – I just started using crystal meth instead, so that didn’t help.

[White Woman, 38 years old]

In this particular case, the participant reported that injection drug use was rooted in part in behavioral cues, and that they were ‘addicted to the needle.’ This participant further noted that, because this treatment approach was pharmacological, there were no supports that assisted in managing drug use patterns. For example:

You get addicted to the needle itself, and that’s not something that detox has really covered, is the addiction to the needle…even if you don’t like the choice of the drugs you got, you still want to be able to inject something…So it’s a weird, uh, it’s a weird place to be when you realize your addiction is to something that people don’t actually treat.

[White Woman, 38 years old]

Other participants alluded to a similar experience, whereby the efficacy of the methadone took away the need to use heroin daily, mitigated opiate withdrawal, and met their primary goals in relation to substance use treatment, but the desire to continue using drugs remained. In these cases, participants commonly described how they were motivated to seek more general relief in relation to their health or social suffering through stimulant use while enrolled in methadone.

DISCUSSION

Our findings illustrate patterns of and reasons for using stimulants while on methadone, where participants’ motivations and instrumental uses of stimulants are informed by their experiences of side effects of methadone, opioid withdrawal, and drug use cravings. Participants reported that the use of stimulants improved their ability to function in their daily lives, including managing their lives within the context of poverty and other structural constraints. The use of stimulants also played an integral role in achieving desired stimulant intoxication effects. Further, these findings demonstrate non-abstinence-based goals associated with methadone, and indicate the desire for continued drug use (stimulants) while achieving better management of opioid use (i.e., reductions in illicit opioid use and avoidance of opioid withdrawal).

Participants in our study reported using cocaine or crystal methamphetamine to combat withdrawal or side effects of methadone. The literature indicates that side effects of methadone, such as sedation and fatigue, may occasionally persist once tolerance has developed and clinicians have titrated people to an appropriate dose (26–28). It is notable that participants reported instrumental uses of stimulants to manage these symptoms to engage in activities of daily living (e.g., attend medical appointments) and engage in income-generating activities. While this might raise questions for some as to whether participants who were stimulant-using were experiencing fatigue from stimulant withdrawal or from the methadone itself, it nonetheless suggests that people find that stimulants can have positive impacts in relation to methadone. Understanding these motivations and instrumental uses of stimulants might aid in the identification of those impacted by side effects, including those who might benefit from other medications (e.g., buprenorphine, slow-release oral morphine, etc.) or possibly other prescriptions (e.g., pharmaceutical stimulants) that reduce the need to engage with the illicit drug market. This is of particular importance given that continued shifts within illicit drug markets are increasing bringing people (including those using stimulants) into contact with adulterants such as fentanyl and others (29, 30). Further, within the context of these potential overdose-related risks, ensuring access to harm reduction interventions (e.g., fentanyl drug-checking strips, overdose prevention sites) will be further necessary to reduce harms among people on methadone who continue to use stimulants (or other drugs).

The current literature demonstrates that many people who use opioids also concurrently use cocaine (19). Studies have documented conflicting evidence on treatment outcomes for this population, with some suggesting that people on methadone reduce their cocaine use once attaining a therapeutic (10, 19, 31) and others showing methadone treatment retention and opioid abstinence is lower in cocaine-using populations (20). Moreover, some studies have suggested a methadone dose related correlation with reduction of cocaine use among people who occasionally use cocaine (19). A Cochrane Collaboration systematic review of 21 studies, including 11 randomized controlled trials with 2279 people randomized and 10 controlled prospective studies with 3715 people followed-up, showed a relative risk of 1.81 with high dose methadone (60 to 100 mg) vs low dose (less than 60 mg) to receive cocaine negative urine samples (10). It has been hypothesized that this is due to the cocaine blocking effects of higher dose opioids such as methadone; in these cases, it is believed that the lack of positive reinforcement from cocaine use might deter people from using it all together (31).

In our study, we see the opposite effect, and instead documented that individuals who did not experience desired intoxication from stimulants reported using more cocaine, sometimes switching from smoking crack cocaine to injecting powdered cocaine. This is characterized by additional health risks related to the route of administration and potential for unsafe injection practices, particularly where social-structural conditions result in high-risk injecting environments (e.g., poor coverage of harm reduction programs, including supervised consumption sites). In addition, the efficacy of opioid blockade might have prompted some in our study population to seek another form of intoxication effect through the use of crystal methamphetamine. It is possible that some of the patterns described by participants in our study are not necessarily due to medication pharmacology and observed trends, but rather can be understood within the context of instrumental substance use. This can be perpetuated where people feel highly vulnerable and continued substance use is a coping within the context of their structural vulnerability (21, 32, 33). It is clear that the initiation and/or intensification of stimulant use once an individual is stable on methadone warrants further attention, and potentially points to the need to complement methadone treatment programs with other programmatic supports. While ensuring that such measures do not raise the threshold of MMT, and thereby exclude or create barriers for highly vulnerable individuals, these supports might be well positioned to address these potential drivers of continued drug use.

This qualitative description of stimulant use and motivations is important in order to create a more nuanced understanding of methadone treatment goals, side effects, and drug interactions in this vulnerable population. In particular, it further demonstrates the need for increased attention to low-threshold methadone treatment programs primarily oriented toward the management of opioid use rather than total drug abstinence, which is becoming more relevant as OAT expands in response to the overdose epidemic. Within this context, methadone treatment requirements, including the expectation that people remain abstinent from stimulants (as well as other drugs), that result in punitive measures like involuntary treatment discontinuation or penalties that increase the threshold of treatment are counterproductive and likely to increase overdose risk among people seeking alternatives amidst an increasingly toxic drug supply (30). Clinicians and pharmacists required to perform ongoing screening for all substance use will also need education in low-threshold approaches, and should be prepared to engage people in harm reduction strategies, such as supervised consumption sites and needle exchanges, while also offering treatment options for stimulant use. Strike et al.’s research has pointed to the need to develop greater consensus among practitioners as to what constitutes low threshold methadone treatment programs, as there is currently an absence of guidelines defining the set of practices associated with this approach. Furthermore, for many physicians, there is often a tension between accepting poly-substance use among those on methadone as a means to enhance retention in the program (16). As such, the expansion of low threshold methadone treatment program models, and development of policies and practices to guide clinicians in relation to these services is necessary. In this regard, our research points to the need to consider the various functions of stimulant use in the lives of people enrolled in methadone treatment, and to work with individuals to support them in addressing their self-defined treatment goals (e.g., managing opioid use). That is, there is an ethical and public health imperative, especially within the context of the current fentanyl-driven overdose crisis, to support people in managing illicit opioid use through methadone treatment and other pharmacotherapies even when they do not seek to achieve drug abstinence to reduce potential harms.

It is important to note that supports, such as transportation access, affordable and nutritious food, quality housing and poverty alleviation, remain much needed treatment supports that should be delivered alongside methadone to increase responsiveness to structural barriers and vulnerabilities that affect daily functioning. It is possible that this might limit the need for some people to use stimulants to live their lives, though it remains that drug abstinence might not also be the goal for some people. Clinicians must be aware that not all individuals wish to cease substance use. Further, they should try to understand reasons for using substances among those engaged in methadone treatment and not penalize them on the basis of ongoing drug use, including imposing treatment requirements that might lead people to discontinue treatment (e.g., limiting take-home dosing).

This study has several limitations. Participants were asked to recount experiences that, for some, happened many years in the past, therefore introducing potential inaccuracies in self-reporting. In discussing treatment experiences, occasionally there is potential for the under-reporting of sensitive and stigmatized behaviors and experiences (e.g. substance use). Settings with different approaches to methadone treatment programs, including more strict monitoring of polysubstance use, might produce different dynamics. Finally, our study setting is characterized by high levels of polysubstance use and participants by their structural vulnerability. This meant that people on methadone were likely to have also used – in this case, concurrently – stimulants and this might not be the case in other settings, particularly where lower levels of polysubstance use are documented.

Overall, our study suggests that in a population that is characterized by structural vulnerability and does not have abstinence-based treatment goals, there are several functional reasons to use stimulants concurrently while on methadone. A deeper and more nuanced understanding of substance use motivators may contribute to more effective strategies for managing concurrent stimulant use while on methadone, and structural interventions and other supports to reduce harm.