Drug Dependence Flashcards
What is addiction
A chronic disease characterised by drug seeking and use that is compulsive, or
difficult to control, despite harmful consequences.
define drug abuse
= is a pattern of drug use in which the users consume the substance in amounts or using methods which are directly or indirectly harmful to themselves or others
define drug dependence
= is an adaptive state that develops after repeated drug use and which results in withdrawal symptoms upon cessation of drug use
define drug tolerance
the diminishing effect of a drug which results after repeated administration at a set dose
define psychological dependence
dependence that involves emotional–motivational withdrawal symptoms (e.g. dysphoria, depression, anhedonia, restlessness)
define physical dependence
dependence that involves significant physical–somatic withdrawal symptoms (e.g. fatigue, nausea, seizures, pain, delirium tremens)
name some examples of - class A - Class B - Class C drugs
- Class A; Heroin, methadone, cocaine, crack cocaine, ecstasy, LSD, magic mushrooms,
- Class B; amphetamines, barbiturates, ketamine, methylphenidate, codeine, cannabis
- Class C; anabolic steroids, benzodiazepines, gamma hydroxybutyrate, gamma butyrolactone
Name the factors that are involved in development of addiction
- Environment
- Drug induced effects
- Genes
describe how genes can lead to addiction
of addiction
- Multitude of genetic factors that increase in the risk of developing addiction
- Some of these are linked to polymorphism and variants in the receptor for opioid
describe how drug induced effects can lead to addiction
- when you take a stimulate this causes pleasure and can cause dopamine release, those who become addicted have a high intensity stimulation of dopamine release in comparison to those who are not addicted who may find displeasure in taking the drug
What is the reward system in the body
The mesolimbic system is referred to as the reward system in the body.
Describe the mesolimbic system
It connects the ventral tegmental area to the nucleus accumbens, and is essential in
drug-dependence.
- it is the REWARD SYSTEM in the body
what is the origin of dopaminergic cell bodes in the midbrain
The VGA is the origin of dopaminergic cell bodies found in the midbrain.
name and describe the stages of addiction
- Binge/intoxication = this give positive reinforcement because this is pleasurable
- Withdrawal and negative affect = negative reinforcement gives you a negative reinforcement aspect
- Preoccupation/anticipation – conditioned positive and negative reinforcement
What are the symptoms of addiction
Bingeing, having loss of control.
Withdrawal.
Cravings.
Intoxifiacation.
describe the mechanism of action underlying withdrawal symptoms
- the ventral tenemental area releases dopamine that will stimulate the dopamine receptors
- neurones receive that input and project back releasing GABA and dynorphin which stimulate Kappa receptors
- Dynorphin will have an inhibitor effect on the VTA neurone and will trigger an unpleasant feeling so in order to get more reward again you need to stimulate it with the drug again
What are the structures in the brain that are involved in development of drug dependence
- Ventral tegmental
- Nucleus accumbens
- Amygdala
- Insula
- Prefrontal cortex
- Hippocampus
neurplasticity during….
Neuroplasticity during development of drug-seeking behaviour
- Brain connectivity changes occur during the development of addiction, there is a gradual involvement of many CNS structures and several neurotransmitter systems
in addiction there is a …
impaired response inhibition and salience attribution
what happens in chronic drug abuse
- there is gradual accumulation in gene expression which changes
- high expression of C for, acute fras and chronic fras
what does alcohol do to GABA transmission and glutamate transmission
- it enhances GABA transmission
- At the same time you decrease the glutaminergic response which is mediated by the NMDA receptors
What is hazardous drinking
regular consumption of over 5 units a day for men and over 3 units a day for women
describe what happens in a cute alcohol intoxication
euphoria followed by depressed mood; slurring of speech, ataxia, general incoordination, pupillary dilatation
What is the acute and long term consequences of alcohol intoxication
- Shrinking of grey matter in alcoholic patients
- Gastritis
- Peptic ulcer disease
- Oesophageal varcies
- Acute pancreatitis
- Alcoholic liver disease
- Wernickes encephalopathy and Korsakoff syndrome – due to thiamine deficiency
what is another word for ecstasy
MDMA
What receptors does MDA target
- 5-HT uptake system
- Dopamine uptake system
- 5-HT2 receptors
- H2 histamine receptors
- α2 adrenergic receptors
What happens in acute MDMA toxicity
- Temperature elevation
- Disseminated intravascular coagulation
- Rhabdomyolysis (blocked by dantrolene) – muslces fall apart, release of protein from the muscles which effect the kidney
- Increased renal reabsorbtion of water
- Hyponatraemia
- Cerebral oedema
What does overuse of MDMA lead to
Overuse of MDMA may lead to irreversible structural alterations in the CAN, such as serotonin axon loss.
What is the main agonist of cannabis
THC
- G protein receptors is what cannabis binds to
what receptors does cannabinoids bind to
- CB1 receptor are concentratred in the Central nervous system – these are the imrpotant one in the CNS
- CB2 receptor are present in peripheral organs and are associated with the immune system
Where are CB1 receptors concentrated
in the CNS
Distribution; neocortex, hippocampus, basal ganglia, brainstem
Where are CB2 receptors
• CB2 receptor are present in peripheral organs and are associated with the immune system
what is the most abdunat G protein receptor in the mammalian brain
CB1
What are the cannabinoid intoxication symptoms
Hypothermia, rigid immobility and decreased motor activity are absent in CB1 knock out animals
how does cannabis work
Cannabinoids, as NTs, produce mostly inhibitory effects by inhibiting glutamate and
GABA release pre-synaptically.
what are the risks of taking cannabis
- Long-term use of cannabis increases significantly the risk of developing schizophrenia and major depression
- Cannabis can act as a “gateway drug”
- Cannabis use-related depression, memory problems and paranoia are heritable
What is cannabidiol
• Cannabidiol (CBD); major non-psychotropic cannabinoid compound present in the plant – potential in treatment-resistant epilepsy – remarkable anti seizure properties
what is sativex and what is cannador
• Sativex® (a product which combines THC and CBD 1:1)
- Cannador®(a product which combines THC and CBD 2:1
What are the key steps in management of addiction
- Detoxification (eliminate the drug from the body)
- Psychological support- counseling
- Medication (when available, e.g. for opioid, tobacco or alcohol addiction)
- Evaluation and treatment for co-occurring mental health problems
- Long-term follow-up
What drugs can help alcohol withdrawal
Alcohol: BZDs or direct GABA agonists. Antiepileptic agents; carbamazepine. Selective serotonin reuptake inhibitors. Thiamine.
What drugs can help nicotine withdrawal
Nicotine:
Nicotine agonists
What drugs can help operate withdrawal
Opiates:
Opioid agonist is methadone.
what has recently be introduced for nicotine withdrawal and what are the side effects
recent introduction of varenicline (a4b2 selective partial agonists at nicotinic receptors
Adverse effects of varenicline: nausea, psychiatric disturbances
What are the long term effects of cocaine
- Cardiovascular problems that include high risk of heart attack and stroke
- Marked cognitive decline
- Persistent psychotic symptoms
- Major depression and anxiety
What research is going in to treat cocaine withdrawal
a) development of anti-cocaine vaccines
b) the antibiotic ceftriaxone has shown potential to attenuate cocaine relapse after abstinence
