Drugs of Abuse Flashcards
what is
- innate tolerance
- pharmacokinetic tolerance
- pharmacodynamic tolerance
- learned tolerance
- conditioned tolerance
- acute tolerance
- reverse tolerance
- and cross-tolerance?
•Types of tolerance:
–Innate (genetically determined lack of sensitivity of drug)
–Pharmacokinetic (change in metabolism of drug after repeat administration)
–Pharmacodynamic (adaptive changes by drug)
–Learned tolerance (compensatory mechanisms though past experience)
–Conditioned tolerance (reflexive adaption to environmental cues)
–Acute tolerance (rapid tolerance after repeat use on single occasion)
–Reverse tolerance (sensitisation)
–Cross – tolerance (tolerance to other drugs in same category)
what is physical dependence?
State of biological adaptation resulting in a drug class-specific withdrawal syndrome produced by
- Abrupt cessation
- Rapid dose reduction
- Decreasing blood level of the drug
- Administration of an antagonist
•Both physical and psychological effects from stopping drug
what is substance dependence?
= addiction
Chronic neurobiological disease with genetic, psychosocial and other environmental factors
•A behaviour pattern of substance abuse characterised by
- Compulsive use (‘wanting without liking’)
- Drug seeking behaviour (craving)
- Continued use despite physical, social, economic harm
- High tendency to relapse after discontinuation
how does drug use transition into addiction?
Intense desire to obtain increasing amounts of particular substance(s) to the exclusion of all other activities
•Self-administration of any drug in a culturally disapproved manner that causes adverse consequences (legal, physical, psychological, social)
What are the variables affecting drug addiction?
- User factors - heredity, metabolism, psychiatric symptoms
- Environment - social setting, community attitudes, other sources of pleasure, employment etc
- Drug - speed of onset, availability, cost, potency, mode of admin.
what type of drug is Alcohhol?
CNS depressant -
Enhances inhibitory transmission through GABAA receptors
- Low doses: inhibition of inhibitory systems leads to expansive, vivacious effects; relaxation, euphoria
- Higher doses: labile mood, sedation, ataxia, amnesia
- Fatal dose: respiratory depression
- Enchances CNS depressent effects of other drugs
- 10% progress to levels which are physically and socially detrimental
What are some effects of chronic alcoholism?
Irreversible neurological effects - dementia and motor impairment
–Thinning of cerebral cortex and degeneration of cerbellum
- Peripheral neuropathy
- Some changes associated with thiamine deficiency – Wernicke Korsakoff syndrome
- Chronic gastritis – gastric mucosa damage
- Pseudo – Cushing syndrome – inhibition of hydrocortisone metabolism
- Impaired testicular steroid synthesis – feminism and impotence
- Fatty liver disease – hepatitis and oesphageal varices
to aid in abstince (maintain the person from alcohol even through withdrawal symptoms), what drugs can we use?
- Disulfiram: acetaldehyde dehydrogenase inhibitor; leads to accumulation of acetaldehyde with alcohol to give flushing, headache, nausea, vomiting * person has to ‘want’ to take the drug- and there is alcohol in a number of substances (food, mouthwash, medications etc)
- Acamprosate: NMDA receptor antagonist and GABAA agonist; reduces craving -
- Naltrexone/nalmefene: opiate antagonist; reduces reinforcing effects of alcohol
what drug do we use for opioid overdose?
Naloxone - but remember that the half life of Naloxone is 1- 3hours, but morphine has a longer half life - so you can come back from an overdose, then go back into respiratory depression when the naloxone wears off
What does MEthadone bind to?
to plasma proteins - therefore only free plasma methadone is able to act as a drug and the majority is bound- which is why it has a really long half life
it helps people reintroduce to society b/c it has a longer half life with less euphoria = less addicition
why are benzodiazepines abused?
b/c it increases frequency of Cl- opening in response to GABA at GABAa receptores (increase neuronal inhibition) =
Nicotine activates what receptors?
nicotinic acetylcholine receptors - located centrallyl, peripherally and at the nueromuscular junciton -
what are some nicotine treatments?
Cycle of change model
–Pre-contemplation, Contemplation, Preparation, Action, Maintenance, Relapse
•Nicotine replacement therapy
-Chewing gum, patches, nasal sprays, inhalers
•Bupropion
– Increases dopamine and noradrenaline pathways in CNS
•Varenicline
–Partial agonist at α4β2 subtype of acetylcholine receptor
•Electronic cigarettes?
methanphetamine addiction can parallel what type of condiiton?
it effects dopaminergic receptors, therefore it can parallel symptoms of parkinsns - can lead to development of parkinson’s disease
