The rates of heroin use and overdose deaths have been steadily growing (Jones et al., 2010). According to the National Institute on Drug Abuse (NIDA), approximately 9,173 Americans died from heroin overdose in 2021 (2023). Heroin belongs to the category of drugs called opioids that act by binding to the mu-opioid receptors in the brain (as mentioned in a review by Contet et al., 2004). Mu-opioid receptors are a part of the body’s opioid system and can be activated by endogenous (e.g., naturally present) opioids (Contet et al., 2004). The opioid system plays an important role in mood, pain relief, stress response, and autonomic functions (as mentioned in a review by Benarroch, 2012). When heroin enters the system, it is processed into morphine, which in turn, binds to the opioid receptors and activates them (as mentioned in a review by Kreek et al., 2012). When these receptors are activated, they cause the release of dopamine, explaining the drug’s pleasurable effects (Johnson & North, 1992). Over time, chronic heroin use leads to tolerance and physical dependence on the drug (Kreek et al., 2012). Abstinence from the drug leads to unpleasant physical and psychological symptoms called withdrawal. As summarized in a review article by Pergolizzi Jr et al. (2020), common opioid withdrawal symptoms include bone pain, muscle aches, chills, insomnia, stomach pain, nausea, vomiting, weakness, anxiety, irritability, and stress. Heroin addiction is maintained through a mechanism called negative reinforcement: without heroin, drug users experience unpleasant side effects of withdrawal, and using the drug helps relieve these negative symptoms, which makes it hard for drug addicts to quit the cycle (Wise & Koob, 2014). 

The current gold standard of heroin addiction treatment is methadone. Methadone is a slow-acting opioid receptor agonist, meaning that it binds to the same receptors that morphine does (as mentioned in a review by Meyer et al., 2021). Methadone reduces withdrawal symptoms and cravings via slow action on the opioid receptors, which does not produce a euphoric effect and reduces the frequency of drug use (NIDA, 2021). A review of randomized controlled studies and observational studies conducted by Ward et al. (1994) supported the effectiveness of methadone in reducing heroin use, crime rates, risk behaviors, and death rates among opioid users. Despite its effectiveness, methadone treatment does not work for everyone. About 15 to 25 % of people receiving methadone drop out of treatment (Johnson et al., 2000). In a longitudinal study of 204 patients undergoing methadone treatment, almost all of them relapsed into using illicit drugs (Davstad et al., 2007). 

Is there a more effective approach to treating heroin addiction? Some European countries have successfully implemented heroin-assisted treatment (HAT; Oviedo-Joekes et al., 2009). Switzerland launched the first study on HAT in 1994 (Meyer et al., 2021). Heroin maintenance therapy provides heroin users with an injectable or oral dose of pharmaceutical-grade heroin (diacetylmorphine) in a safe, controlled environment (Meyer et al., 2021). Although it may seem counterintuitive to treat heroin addiction by providing addicts with heroin, the goal of this treatment is to accommodate drug users who did not benefit from methadone therapy and integrate them into society (Güttinger et al., 2003). A six-year follow-up of the initial Swiss study showed that the positive changes gained in treatment persisted even after its termination (Güttinger et al., 2003). People who stayed in treatment consumed fewer illicit drugs, had less debt, fewer illegal sources of income, and fewer addicted friends, which suggests the long-term effectiveness of treatment (Güttinger et al., 2003). Compared to methadone, heroin-assisted therapy is more effective (Haasen et al., 2018; Oviedo-Joekes et al., 2009). People who receive medical heroin are more likely to stay in treatment and use fewer illicit drugs and participate in fewer illegal activities (Oviedo-Joekes et al., 2009). They also report better physical and mental health than users who receives methadone (Haasen et al., 2018). However, diacetylmorphine is still an opioid and can produce serious side effects, including seizures and overdoses, emphasizing the importance of having medical interventions available in heroin assistance facilities (Oviedo-Joekes et al., 2009). 

Methadone remains the first line of treatment for heroin addiction, but randomized controlled trials for heroin-assistance treatment show promising results. As with any addiction, it is important to address the factors that led to drug use and provide chronic opioid users with counseling, informational resources, housing, and employment as part of a holistic approach.

References

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