By Sarah Garland

Speed. Meth. Crank. Ice. Crystal meth. They’re all names for methamphetamine — a harmful class of illicit drug that can be made from inexpensive medicines commonly found in drug stores. Consuming methamphetamine, by smoking, injecting, or snorting, can cause feelings of euphoria. However, other short-term effects include elevated heart rate and blood pressure, weight loss, headache, dizziness, vomiting, and increased body temperature. Those who use methamphetamine long-term may experience severe dental decay (i.e., “meth mouth”), psychosis, paranoia, and the feeling that bugs are under their skin.

In recent years, the medical community has been grappling with the severity and scale of the opioid crisis, which remains problematic still. Yet there are other drugs on the scene that contribute to the picture of addiction in Canada. According to the Canadian Centre on Substance Use and Addiction (CCSA), methamphetamine use remains relatively rare — at less than one per cent of the population (though estimates vary and reporting on use is not very reliable). However, there has been a 590 per cent increase in methamphetamine possession incidents from 2010 to 2017. This suggests that methamphetamine may now be more easily accessible. Unlike opioids, there is no legal use for methamphetamine, and there is no legal alternative.

Managing medical issues around methamphetamine use, such as the drug’s potential impact on pregnant persons, is challenging. Methamphetamine withdrawal is a particular challenge, as people who are coming down from methamphetamine-related highs typically have higher rates of non-compliance, aggression, and violence when they are seen in emergency departments or acute care settings. When it comes to questions of evidence and best practice, health care decision-makers can turn to CADTH — an independent agency that finds, assesses, and summarizes the research on drugs and medical devices. CADTH’s Rapid Response program responds to health care provider and decision-maker requests for timely and up-to-date evidence reviews tailored to meet their specific needs.

Since December 2018, CADTH conducted several Rapid Response reviews on the treatment of crystal methamphetamine withdrawal. One looked for evidence on drug interventions for managing acute withdrawal in adults who misuse methamphetamine. Two randomized controlled trials were identified — one found pexacerfront to be effective for managing methamphetamine cravings during withdrawal, and the other found buprenorphine to be effective. A systematic review was also identified, which concluded that intravenous lorazepam and droperidol appear to be an effective treatment for patients with methamphetamine-related agitation in the emergency department, and that aripiprazole, haloperidol, and quetiapine may be effective at managing methamphetamine-induced psychosis. The systematic review also suggested that isradipine could be effective at managing methamphetamine-induced high blood pressure. One evidence-based guideline that was identified recommends that benzodiazepines be considered a first-line treatment option for the management of severe agitation, aggressiveness, or psychosis from methamphetamine withdrawal.

The CADTH review noted, however, that there is a need for larger, controlled studies and longer-term follow-up of patients once they are discharged back into the community — which can be challenging when working with people experiencing addiction. There are also research gaps when it comes to psychological or physical interventions to manage acute withdrawal symptoms; the CADTH report did not identify any non-pharmacological strategies. Based on these limitations, it is uncertain how these interventions compare to non-pharmacological strategies and what a holistic view of withdrawal management might be.

Another CADTH review looked at guidelines for treatment provided immediately after acute detoxification and post-treatment care for patients with methamphetamine addiction. This review identified one evidence-based guideline that recommends psychotherapeutic and pharmacologic treatment options as well as structured exercise programs. The guideline also included weak recommendations for the use of tranquilizers to manage short-term agitation and the use of antipsychotics as needed. The guideline recommends against the use of sertraline to achieve abstinence because of the side effects associated with it.

CADTH has also conducted evidence reviews on safe rooms for patients experiencing crystal methamphetamine-induced psychosis, treatment of neonatal abstinence syndrome, and withdrawal management or treatment of persons who are pregnant and addicted to crystal meth. None of these reviews, however, found any relevant literature. Although there is a need for more information on the treatment of pregnant persons and infants experiencing withdrawal, conducting research on this topic is challenging, given that methamphetamine is an illicit substance.

While the CADTH reviews looked at slightly different populations and interventions, it remains clear that there is a need for evidence in this space. The CCSA cites stigma (the negative stereotypes about persons with addictions) as one of the largest barriers to persons seeking and receiving treatment. It can be challenging for persons with addictions to access care, and it appears to be additionally challenging for health care workers to know how best to support persons with methamphetamine addictions. Despite the evidence gaps in this area, there appear to be some evidence-based guidelines to help guide acute withdrawal, acute detoxification, and post-treatment care, and some research on pharmacotherapies that may be effective for patients.

And if you would like to learn more about CADTH, visit cadth.ca, follow us on Twitter @CADTH_ACMTS, or speak to a Implementation Support team member in your region: https://cadth.ca/contact-us/liaison-officers

Sarah Garland is a Knowledge Mobilization Officer at CADTH.