heroin. very addictive and illegal! belongs to the opioid family - derived from the opium poppy...
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Heroin
Very addictive and illegal!
Belongs to the opioid family
- Derived from the opium poppy (Papaver somniferium)
- Semi-synthesized from morphine providing a stronger and more immediate effect.
Pain reliever and cough suppressant
http://upload.wikimedia.org/wikipedia/commons/8/87/Opium_poppy.jpg
Street Names: - Black Tar, Mud, Smack, Junk, China White, Mexican Brown,
Horse, H, Skag, Dope=
Diacetylmorphine: the International Nonproprietary Name
Diamorphiane: the British Approved Name; legally prescribed drug
The -OH group of morphine is replaced by –OCH3 producing codeine
Both –OH groups of morphine replaced by –OCOCH3 produces heroin
Morphine
Codeine
Heroin
N
O
O
O
CH3
CH3
O
CH3
O
O
O
OH
CH3
N
CH3
N
O
HO
OH
CH3
Morphine: - used for medicinal reasons- prescribed pain killer
Heroin: - illegal to manufacture, possess, or sell- used as a pain-killer as well as a recreational drug- highly addictive!
Pure Heroin White powder Has a bitter taste
http://www.pbs.org/wnet/wideangle/shows/centralasia/images/heroin5.jpg
- The opium gum is converted to morphine in labs near the fields and to heroine in labs near the producing countries.
- The dealers then dilute it with sugars, starch, or powder milk prior to selling
- Sometimes quinine is also added to imitate the bitter taste so the user is unable to tell the quantity of heroin in the sample. http://www.spiegel.de/img/0,1020,817155,00.jpg
Can be mixed with other narcotics for various effects
Sniffed, snorted or smoked for high purity
Powder form can be heated to melt and then injecting the liquid form into veins using a syringe- 3-5 times more potent than the powder form.
Easily overdosed and can lead to death
Possible transmission of HIV and other diseases due to the sharing of needles [1-3]
http://i.current.com/images/asset/889/022/26/PN7mpv.jpg
http://www.russianspy.org/wp-content/uploads/2006/11/heroin.jpg
Varies in color from white to dark brown due to additives or impurities left from the synthesis process
Comes in granule, powder, solution, or pill forms
The dealers then dilute it with sugars, starch, or powder milk prior to sellingso the user is unable to tell the quantity of heroin in the sample
Sometimes quinine is also added to imitate the bitter taste.
http://upload.wikimedia.org/wikipedia/commons/archive/5/5b/20070725121556!Heroin_asian.jpg
After intake, heroin crosses the blood-brain barrier:- Converts into morphine by removal of the acetyl groups
Binds quickly to µ,κ, or δ opioid receptors- µ: results in analgesia, euphoria, CNS depression, respiratory depression, and miosis- Κ and δ: also analgesia but kappa receptors are mostly found in the spine.
Feeling of a quick surge of pleasure targeted in the gut
“High” or a “rush”
Pain relief [2,3]
The intensity dependant on dose of heroin is taken in and therefore how quickly the heroin enters the brain and binds to the µ-opioid receptors
Warm flushing of the skin
Dry mouth
Extremities feel heavy
Nausea and Vomiting
Several hours of drowsiness
Clouded mental function by effect on the CNS
Slows the heart as well as breathing
http://www.vlib.us/medical/HMSO/skin1.jpg
Flushing of the skin
Alters the Paleomammalian brain Manipulates emotions with increased feelings of pleasure and
euphoria
Blocks pain signals transmitted by the spinal cord
Changes the brain stem Controls reflexes Slows down breathing [2,3]
Addiction Increased tolerance Physical dependence Euphoric reward decreases Need higher doses for the same effect Increased repetition
Severe shortening of breath or suffocation
Increase in intensity and occur more often Restlessness Insomnia Muscle and bone damage Can cause death to the fetus of a pregnant user [2-4] Major affect on gastric movements Cold sweats Quivers Nail biting Yellowing and darkening of the nails
Endogenous Substance: The natural neurotransmitters are endorphins Used to combat pain
Endorphins production reduced when present
Difference- Endorphins: naturally produced by the body and are quickly broken down after they are released;
- Heroin: more addictive; stays in the body for a longer period of time
Reduced endorphin production creates strong dependence on heroin [5]
Mimicry of Endorphins:
Heroin is first converted into morphine then mimics endorphins, creating a sense of well-being
Direct agonist that directly binds to the µ-opioid receptor and activates it
Mimics and substitutes for endorphins
Leads to increases in dopamine release in the limbic system
Increased dopamine concentration produces the “high” [6]
Pleasurable sensation from heroin occurs due to the reward centre being stimulated
Dopamine: Key neurotransmitter in the reward system
Three types of neurons are involved in the reward process: Endorphin neurons GABA neurons Dopamine neurons [4,5,7]
Dopamine Neuron
GABA Receptors
Dopamine
GABA Neuron
GABA
Electric Signal
Incentive
1. Normally, Dopamine is released continuously
2. Neurotransmitter GABA inhibits the release of dopamine
µ-OpioidReceptors
Dopamine intercepted No reward
µ-Opioid Receptors
Inhibitory Signal
(Normal Conditions)
Dopamine Neuron
GABA Receptors
Dopamine
GABA Neuron
GABA
Electric Signal
µ-Opioid Receptors
Endorphin Neuron
Endorphin
Incentive
1. Electrical signal is applied on an endorphin neuron, the vesicles are exocytosed and are able to bind to the µ-opioid receptors on the GABA neuron [5]
2. When bound, the opioid receptors prevent electric signals from releasing GABA [5,7]
GABA not released
Dopamine free to proceed to target
3. Inhibition of GABA allows the dopamine neuron to release dopamine, resulting in the feeling of pleasure and well-being [5,7].
Inhibitory Signal
µ-Opioid Receptors
Endorphins immediately begin dissociating and break down after being bound to opioid receptors
Endorphin Neuron
Dopamine Neuron
Dopamine
Electric Signal
Endorphin
Inhibitory Signal
The dopamine neuron possesses µ-opioid receptors.
Binding inhibits dopamine from reaching its target.
Endorphins can therefore produce stimulatory and inhibitory effects [5].
µ-Opioid Receptors
Dopamine Neuron
GABA Receptors
Dopamine GABA Neuron
GABA
Electric SignalEndorphin Neuron
Endorphin
Reward
Dopamine free to proceed to target
Inhibitory Signal
GABA not released
(Heroin Conditions)
Morphine
Heroin converts into morphine and mimics the endorphins by binding tightly to the µ-opioid receptors. As the GABA supply decreases, dopamine is more free to proceed to its target and stimulate pleasurable reward [5,7].
µ-Opioid Receptors
µ-Opioid Receptors
Morphine also binds to µ-opioid receptors of the dopamine neuron, decreasing inhibition of dopamine activity
However, the release of dopamine is independent as it is not being inhibited or intercepted by the inhibitory signals due to the binding of morphine to the GABA neuron µ-opioid receptors [7]
Endorphin
Morphine
Endorphin Neuron
P Neuron
Adjacent Neuron
µ-opioid Receptors
Adjacent Neuron Receptors
Morphine: competitive agonist as it binds to receptors on the P neuron, blocking the release of more P substance (pain signals) [5,7]
Morphine also acts as a competitive antagonist as it will also block the receptors on the adjacent neuron from receiving P substance [5,7]
P SubstancePrevention of P Substance release
Morphine eventually dissociates from receptors and slowly breaks down
Difference:- Endorphin: short term effect; dissociate almost immediately; quick break down
- Heroin: longer lasting; stays bound for a longer period of time
Heroin can easily lead to overdose and can most dangerously cause suffocation
Can severely affects breathing rhythm- neurons regulating breathing patterns also possess µ-opioid- morphine acts like an antagonist, inhibiting signal transmission to the breathing muscles and slowing down the breathing
An overdose can cause lungs to collapse and therefore prevent all breathing causing suffocation [2-5]
Heroin contracts the pupils to as small as less than one millimete Many areas in the gastro-intestinal tract contain many opioid receptors
Heroin inhibits bowel activity leading to constipation
The vomiting centre is stimulated by heroin
The cough centre is suppressed by heroin
After continuous use, ability to feel pleasure is reduced or terminated if heroin is not taken often
Body has reduced or complete inability to release dopamine in a natural way [2-5]
OPIOID AGONISTS Methadone: standard drug treatment for heroin addicts
Mimics morphine Binds to and activates the same µ-opioid receptors as
heroin/morphine, and produces the same cellular effects as heroin/morphine
PRO: more sterile, no crime or violence involved, reduces relapse CON: still harmful!
Levomethadyl Acetate Hydrochloride (LAAM) produces effects similar to methadone in the brain and to reduce relapse
Longer duration of action than methadone [8]
OPIOID ANTAGONISTS Naloxone
Reduces heroin craving post-withdrawal Induces rapid detoxification in heroin addicts
Naltrexone similar to naloxone, but is longer-acting
Nalmefene Most effective since block more µ-opioid receptors
Buprenorphine mimics the brain’s natural neurotransmitters, resulting in gradual reduced withdrawal
Partial agonist Acts as both an opioid agonist and antagonist [8]
[1] Clatts MC, Giang LM, Goldsamt LA, Yi H. 2007. Novel Heroin Injection Practices: Implications for Transmission of HIV and other Bloodborne Pathogens. American Journal of Preventive Medicine; 32(6): 226-233.
[2] Michels II, Stöver H, Gerlach R. 2007. Substitution treatment for opioid addicts in Germany. Harm Reduction Journal; 4: 5.
[3] Jaffe JA and Kimmel PL. 2006. Chronic Nephropathies of Cocaine and Heroin Abuse: A Critical Review. Clinical Journal of the American Society of Nephrology; 1: 655-667.
[4] Lenoir M and Keiflin R. 2006. Heroin Addiction: Anticipating the Reward of Heroin or the Agony of Withdrawal. The Journal of Neuroscience; 26(36): 9080-9081
[5] Belgraver M, Erkamp B, Dragutinovic, Kerssemakers R. 2007. Heroin and the Brain. Jellinek Preventie Amsterdam:
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[6] Terenius L. 1997. Opioid Peptides and Receptors in Drug Abuse. Department of Clinical Neuroscience; 11: 171-176.
[7] Yao L, McFarland K, Fan, Peidong, Jiang Z, Inoue Y, Diamond I. 2005. Activator of G protein signaling 3 regulates opiate activation of protein kinase A signaling and relapse of heroin-seeking behavior. Proceedings of the National Academy of Sciences of the United States of America; 102(24): 8746-8751.
[8] Wasilow-Mueller S and Erickson CK. 2001. Drug Abuse and Dependency: Understanding Gender Differences in Etiology and Management. Journal of the American Pharmaceutical Association; 41(1): 78-90.