Drug dependance Flashcards
Drug abuse
Pattern of drug use in which users consume substance in amounts or using methods which are directly or indirectly harmful to themselves or others
Drug dependence
An adaptive state that develops after repeated drug use and which results in withdrawal symptoms upon cessation of drug use
Drug tolerance
Diminishing effect of a drug which results after repeated administration at a set dose
Psychological dependence
Dependence that involves emotional-motivational withdrawal symptoms
Physical dependence
Dependence that involves significant physical-somatic withdrawal symptoms
Class A drug
Heroin Methadone Cocaine Ecstasy LSD
Class B drug
Amphetamines
Ketamine
Codeine
Cannabis
Class C drug
Anabolic steroids
Benzodiazepines
Opiates target
Mu and delta opioid receptors
Cocaine targets
DA, NAd and 5HT uptake systems
Amphetamine targets
Monoaminergic transmission uptake systems
TAAR1 agonist
Ethanol targets
GABAa and NMDA receptors
Nicotine targets
Nicotinic receptors
Cannabinoids target
CB1 receptors
Ketamine targets
NMDA glutamate receptors
Hallucinogens target
5HT2a receptors
Barbiturates and benzodiazepines target
GABAa receptors
Genes of addiction
OPRM1
SLC6A3
Reward circuit- dopaminergic
Dopaminergic projection from ventral tegmental area –> nucleus accumbens
Withdrawal mechanisms
Drugs of abuse can up-regulate the opioid peptide dynorphin
Activation of kappa opioid receptors can trigger dysphoria, by reducing dopamine release
Addicts- dopamine receptors + cerebral metabolism
Reduced availability D2 receptors + reduced metabolism
Core clinical symptoms of addiction
Intoxication
Bingeing
Withdrawal
Craving
Acute alcohol ingestion
Depressed excitatory transmission + potentiated inhibitory transmission
Grey matter in alcoholics
Shrinkage
MDMA cellular targets
5-HT uptake system Dopamine uptake system 5-HT2 receptors H2 histamine receptors α2 adrenergic receptors
Acute MDMA toxicity
Temperature elevation Disseminated intravascular coagulation Rhabdomyolysis (blocked by dantrolene) Increased renal reabsorbtion of water Hyponatraemia Cerebral oedema
Cannabinoids
Bind to CB1 + CB2 receptors
CB1- concentrated in CNS
CB2- peripheral organs + associated with immune system
Mainly inhibitory effects- medium spiny neurones, pyramidal cells
Disulfiram
Allows build up of toxic breakdown product of acetaldehyde
Used for alcoholics