Dr. Ruwan M Jayatunge

Heroin (also known as diacetylmorphine or morphine diacetate) is an opioid analgesic. Heroin is processed from morphine, a naturally occurring substance extracted from the seed pod of certain varieties of poppy plants. It has high addictive potential. Heroin is most often injected, snorting—inhaling the powder through the nose or smoking. Heroin produces a downer” effect that rapidly induces a state of relaxation and euphoria.

Heroin modifies the action of dopamine in the nucleus accumbens and the ventral tegmental area of the brain – these areas form part of the brain’s ‘reward pathway’. Once crossing the blood-brain barrier, heroin is converted to morphine, which acts as a powerful agonist at the mu opioid receptors subtype. Heroin binds and activates mu-opioid receptors of the brain. Mu opioid receptors mediate positive reinforcement following direct (morphine) or indirect (alcohol, cannabinoids, nicotine) activation (Contet et al., 2004). When MORs are activated in the reward center of the brain, they stimulate the release of the neurotransmitter dopamine, causing a sensation of pleasure (Johnson & North, 1992).

One of the most significant effects of heroin use is addiction. Also with regular use a tolerance develops, where more and more heroin is needed to achieve the same effect. Heroin addiction is associated with profound and negative impacts on physical and mental health. In addition it has devastating social and economic consequences.

Heroin use causes major health problems, including heart disease, blood borne pathogens from injecting (HIV/HCV/HBV) and dental problems. Collective damage from injecting drugs includes cellulitis, abscesses and inflammation of the lining of the heart.  As the heroin user becomes more dependent and loses employment, the normal trajectory indicates that the heroin dependent individual will commit crimes to support their habit.

Heroin causes irreversible changes in the neuronal and hormonal systems (Ignar & Kuhn, 1990).

Wang and colleagues (2012) highlighted that repeated heroin use changes the physical structure and physiology of the brain (Wang et al., 2012). Heroin is a central nervous system depressant. Heroin deteriorates brain’s white matter impacting decision-making abilities and behavior regulation (Liu et al., 2011).  Habitual heroin uses suffer from depression and antisocial personality disorder.  Heroin addiction contributes to health and social problems mainly causing dependency, mortality and morbidity.

Heroin is a   respiratory depressant and heroin overdose is a major contributor to the excess mortality of heroin addicts (Jolley et al., 2015). Mortality rates for heroin dependent persons are extremely high. Over 50 percent of heroin dependent persons will be dead before the age of 50, and the mean age of death is 30 (Darke et al., 2007).  Their risk of suicide is 14 times that of the general population (Hulse et al., 1999).

A range of treatments exist for heroin addiction, including medications and behavioral therapies. Research shows that combining treatment medications, where available, with behavioral therapy is the best way to ensure success for most patients. For some patients the beginning of treatment is detoxification — controlled and medically supervised withdrawal from the drug. Also Methadone maintenance treatment (MMT) is one of the effective and safe options for treatment of heroin dependence.

Methadone treatment has been used for more than 30 years to effectively and safely treat opioid addiction.  Buprenorphine is a particularly attractive treatment for heroin addiction because, compared with other medications, such as methadone, it causes weaker opiate effects and is less likely to cause overdose problems.  According to Sun et al (2015) Methadone maintenance treatment has significantly reduced criminal activity, and improved employment rate and social well-being, of clients of the MMT programme.

References

Contet, C ., Kieffer, B.L., Befort, K.(2004). Mu opioid receptor: a gateway to drug addiction. Curr Opin Neurobiol. 2004 Jun;14(3):370-8.

Darke, S., Degenhardt, L. & Mattick, R. (2007a). Mortality amongst illicit drug users: Epidemiology, causes, and intervention. Cambridge: Cambridge University Press.

Hulse, G.K., English, D.R., Milne, E., Holman, C.D.J. (1999). The quantification of mortality resulting from the regular use of illicit opiates. Addiction. ;94:221–229.

Ignar, D.M., Kuhn, C.M.(1990). Effects of specific mu and kappa opiate tolerance and abstinence on hypothalamo-pituitary-adrenal axis secretion in the rat. J Pharmacol Exp Ther 255(3):1287–1295.

Johnson, S.W ., North, R.A. (1992).Opioids excite dopamine neurons by hyperpolarization of local interneurons. J Neurosci 12(2):483–488.

Jolley, C.J. , Bell, J. , Rafferty, G.F. , Moxham, J ., Strang, J.(2015).Understanding Heroin Overdose: A Study of the Acute Respiratory Depressant Effects of Injected Pharmaceutical Heroin. PLoS One.  23;10(10):e0140995.

Kane-Willis, K., Schmitz, S.J., Bazan, M., Narloch, V.F., Wallace, C.B. Understanding suburban heroin use. Roosevelt University. https://www.robertcrown.org/files/Understanding_suburban_heroin_use.pdf. Accessed November 12, 2015.

Liu, J.; Qin, W.; Yuan, K.; Li, J.; Wang, W.; Li, Q.; Wang, Y.; Sun, J.; von Deneen, K.M.; Liu, Y.; Tian, J. (2011). Interaction between dysfunctional connectivity at rest and heroin cues-induced brain responses in male abstinent heroin-dependent individuals. PLoS One 6(10):e23098.

Sun, H.M., Li, X.Y.,Chow, E.P.F.; Li, T., Xian, Y., Lu, Y.H. Tian, T.; Zhuang, X,. Zhang, L. (2015).Methadone maintenance treatment programme reduces criminal activity and improves social well-being of drug users in China: A systematic review and meta-analysis’, BMJ Open, vol. 5, no. 1.

Wang, X.; Li, B.; Zhou, X.; Liao, Y.; Tang, J.; Liu, T.; Hu, D.; and Hao, W. (2012).Changes in brain gray matter in abstinent heroin addicts. Drug Alcohol Depend 126(3):304–308.