Heroine creates a reoccurring need to stimulate the opiate centers (receptors) of the brain. These centers superseded or become our logic centers. Reason CANNOT be expected calm the urge. How many times does family try to reason with an addict before they give up from lack of energy and frustration? Addiction like this cannot be reasoned with.
An “opioid” is any narcotic not derived from opium. Indicating substances such as enkephalins or endorphins occurring naturally in the body that can affect on the brain to decrease the sensation of pain are also classified as opioids. Narcotic compounds found in natural opium latex are classified as opiates, not opioids. Common examples of opioids are: oxycodone, hydrocodone, oxymorphone, hydromorphone, methadone, and several others.
Opiates are analgesic alkaloid compounds found naturally in the opium poppy plant Papaver somniferum. The psychoactive compounds found in the opium plant include morphine, codeine, and thebaine. The term opiate should be differentiated from the broader term opioid, which includes all drugs with opium-like effects, including opiates, semi-synthetic opioids derived from morphine (such as heroin, hydrocodone, hydromorphone, oxycodone, and oxymorphone), and synthetic opioids which are not derived from morphine (such as fentanyl, buprenorphine, and methadone).
When taken orally, heroin undergoes extensive first-pass metabolism via deacetylation, making it a prodrug for the systemic delivery of morphine. When the drug is injected, however, it avoids this first-pass effect, very rapidly crossing the blood–brain barrier because of the presence of the acetyl groups, which render it much more fat soluble than morphine itself. Once in the brain, it then is deacetylated variously into the inactive 3-monoacetylmorphine and the active 6-monoacetylmorphine (6-MAM), and then to morphine, which bind to μ-opioid receptors, resulting in the drug’s euphoric, analgesic (pain relief), and anxiolytic (anti-anxiety) effects; heroin itself exhibits relatively low affinity for the μ receptor. Unlike hydromorphone and oxymorphone, however, administered intravenously, heroin creates a larger histamine release, similar to morphine, resulting in the feeling of a greater subjective “body high” to some, but also instances of pruritus (itching) when they first start using.
Both morphine and 6-MAM are μ-opioidagonists that bind to receptors present throughout the brain, spinal cord, and gut of all mammals. The μ-opioid receptor also binds endogenous opioid peptides such as β-endorphin, Leu-enkephalin, and Met-enkephalin. Repeated use of heroin results in a number of physiological changes, including an increase in the production of μ-opioid receptors (upregulation). These physiological alterations lead to tolerance and dependence, so that cessation of heroin use results in a set of remarkably uncomfortable symptoms including pain, anxiety, muscle spasms, and insomnia called the opioid withdrawal syndrome. Depending on usage it has an onset 4–24 hours after the last dose of heroin. Morphine also binds to δ– and κ-opioid receptors.
Like most opioids, unadulterated heroin does not cause many long-term complications other than dependence and constipation. The average purity of street heroin in the UK varies between 30% and 50% and heroin that has been seized at the border has purity levels between 40% and 60%; this variation has led to people suffering from overdoses as a result of the heroin missing a stage on its journey from port to end user, as each set of hands that the drug passes through adds further adulterants, the strength of the drug reduces, with the effect that if steps are missed, the purity of the drug reaching the end user is higher than they are used to.Intravenous use of heroin (and any other substance) with non-sterile needles and syringes or other related equipment may lead to:
The risk of contracting bacterial or fungal endocarditis and possibly venous sclerosis
Poisoning from contaminants added to “cut” or dilute heroin
Decreased kidney function (although it is not currently known if this is because of adulterants or infectious diseases)