Drugs of dependence and antidepressants Flashcards Preview

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Flashcards in Drugs of dependence and antidepressants Deck (44):
1

Define drug dependence?

What does it arise from?

State where drug use becomes compulsive, taking precedence over other needs 

Arises from drug abuse

2

Define drug abuse?

Use of illicit substances (or illicit use of legal substances) characterised by recurrent and clinically significant adverse consequences 

3

Describe the relationship between drug abuse and drug dependence?

Drug dependence arises from drug abuse 

4

Describe the common reasons for drug abuse?

Rewarding effects of psychoactive drugs (positive reinforcement)

Habituation or adaptation

5

List some commonly abused drugs?

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6

Which circuits are thought to be involved in drug abuse and addiction?

Reward/ salience areas

Memory/learning areas

Motivation/drive areas

Inhibitory control areas

 

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7

What is the key to the positive reinforcement provided by drugs of dependence and abuse?

Increase in dopamine in nucleus accumbens 

8

What are the key NTs modulating dopaminergic transmission?

Ach, serotonin, NA

GABA, glutamate

Opioids

9

To which drug class does amphetmaine belong?

CNS stimulant

10

Describe the effect of amphetamine on NTs?

Releases Da, 5-HT and NA in CNS

11

Which variables alter the effects of amphetamine?

Mood

Personality

Environment

Dose

12

Describe the effects of amphetamine?

Mood elevation/euphoria

Increased locomotor activity

Stereotypic behaviour 

Improved physical and mental performance (fatigue postponed, confidence, faster performance but less accuracy)

 

13

Describe the effects of amphetamine overdose?

Anxiety, nervousness and physical tension

Tremors, confusion, dizziness, time passes quickly

Hyperthermia, tachycardia, increased BP, vascular collapse

Amphetamine psychosis - hallucinations 

14

Why does amphetamine dependence occur?

When is depedence more likely to occur?

Related to dopaminergic actions in nuclear accumbens

More likely to occur in those starting at a 'lower basleine' (i.e. depressives, lonely)

15

Describe the effect of amphetamine on appetite?

Why does this occur?

Appetite suppressant

Thought to be an effect of 5-HT

16

What is MDMA?

MethyleneDioxyMetAmphetamine

'Ecstasy'

 

17

Describe the effects of MDMA on NTs?

Release DA and 5-HT

18

Describe the effects of MDMA?

Stimulant and hallucinogenic effects

19

Describe the adverse effects of MDMA?

Psychological dependence

Increased HR and BP

Disrupted thermoregulation (chills, sweating)

Potential degeneration of 5-HT and DA neurons

20

What is LSD?

Which drug class does is belong to?

Lysergic acid diethylamide

Hallucinogen 

21

Describe the effects of LSD?

Visual, auditory and tactile hallucinations (sesnory modalitites confused)

Thought processes disturbed but aware

22

Describe the adverse effects of LSD?

Tolerance

Dependence not really an issue (aversive rather than reinforcing)

23

Describe the action of LSD in the body?

Agonist at 5-HT2 receptors 

24

Describe the effects of caffeine?

Increases alertness, well-being

Delays onset of sleep

Stimulates mental activity


 

25

To which drug class does caffeine belong?

What is its action?

Methylxanthine

Adenosine antagonist, PDE inhibitor

26

Describe the effect of dependence in caffeine?

No strong reinforcing effect in animals

Social aspect in humans 

27

What is D9-THC?

Active ingredient in cannabis

28

To which drug class does D9-THC belong?

CNS depressant 

29

Describe the effects of D9-THC?

Very subjective; influenced by characteristics of drug and individual

Sharpened sensory awareness, increased intensity of sounds and sights 

Relaxation, feeling of well-being

30

Describe the effect of dependence with D9-THC use?

Some evidence of physical and psychological dependence in heavy users

31

Where does D9-THC act in the body?

Describe its effect?

Cannabinoid receptors (GPCRs) > inhibits adenylate cyclase > inhibition of transmission

Two receptor subtypes: CB1 and CB2

32

Describe the effects of ethanol?

Behavioural effects: subjective; increased confidence, euphoria, agression, mood swings

Motor effects: loss of coordination, slurred speech

Tissue effects: cardiovascular protection, liver damage, neurodegeneration, foetal impairment 

33

To which class of drugs does does ethanol belong?

Describe its action?

CNS depressant

Can inhibit Ca channel opening, enhance GABA action, inhibit glutamate receptors 

34

Describe the effects of tolerance and dependence with ethanol use?

Marked tolerance, due to pharmacokinetic effects of enhanced clearance

Physical dependence, rather than psychological (well defined abstinence syndrome)

35

Describe the three generations of antidepressant drugs?

1st: tricyclic antidepressants, MAO inhibitors

2nd: SSRIs, SSNRIs

3rd: novel monoaminergic drugs, non-monoaminergic drugs 

36

Describe the pharmacological action of tricyclic antidepressants?

Describe their selectivity?

Inhinit neuronal uptake of NA and serotonin 

Anatgonise a-adrenoceptors, MuscR, HA receptors and serotonin receptors 

Poor selectivity (based around somehow interfering with uptake of NA and serotonin

37

Give three examples of tricyclic antidepressants?

Imipramime

Amitryptiline

Doxepin

38

Describe the onset of clinical effects of tricyclic antidepressants?

Takes weeks to develop

39

Describe the therapeutic window of tricyclic antidepressants?

Narrow

Limited efficacy, side effects become a problem 

40

Describe the half lives of tricyclic antidepressants?

What impact does this have on dosage?

Longish half-life

Gradual accumulation possible, so slowly developing side effects

Start dose low to avoid side effects, then increase

41

Describe the pharmacological action of monoamine oxidase inhibitors?

Increase levels of 5-HT, NA and DA

42

Describe the pharmacological effect of SSRIs?

Selective for blocking 5-HT uptake 

43

Describe the side effects of SSRIs?

Nausea

Insomnia

Agitation

Weight change

Loss of libido

44