Therapy Analysis - Drug addiction
Narcotics
The opiate narcotic heroin (the street name of diamorphine) activates mu opioid receptors in the brain that are usually activated by endogenous substances. The stimulation of these opioid receptors from heroin leads to feelings of intense euphoria, known as a rush, accompanied with flushing of the skin, and heavy extremities. This is also linked to an increase in the neuronal firing of dopaminergic cells. Following this rush, the user experiences an alternately wakeful and drowsy state due to the clouding of mental functioning due to the depression of the central nervous system.
Long-term effects occur after a long period of repeated use, and chronic users may develop infection of the heart lining and valves, abscesses, collapsed veins and liver disease. In a similar way to other drugs, mainly cocaine, repeated heroin use is triggered by its often devastating physical withdrawal effects. This withdrawal may occur as early as a few hours after the last administration in regular abusers and includes restlessness, muscle and bone pain, insomnia, cold flashes with goose bumps, kicking movements and diarrhoea and vomiting, which all produce drug craving.
In addition to the use of a replacement therapy, such as methadone, opioid antagonists such as naltrexone are commonly used to treat opiate addiction. Currently in Phase III trials for the 6mth treatment of opioid addiction is Titan Pharmaceuticals' subcutaneous formulation of buprenorphine, Probuphine, and Indevus has an extended release formulation of naltrexone in Phase II trials.
