drugs of abuse

Question 1

addiction vs physical dependence

Answer 1

addiction: impaired control over use, compulsive, craving

physical dependence: adapted state, causing specific withdrawal syndrome.

produced by abrupt cessation, sudden dose reduction, admin antag

Question 2

addictive drugs activate which pathway?

Answer 2

mesolimbic dopamine system

Question 3

which receptors does ethanol affect

Answer 3

• GABAA receptors
• Kir3/GIRK channels
• Adenosine reuptake
• Glycine receptors
• NMDA receptors
• 5-HT3 receptors

Question 4

ethanol withdrawal

Answer 4

tremor, n/v, sweating

seizures 24-48 hours

delirium tremens 48-72 horus

Question 5

tx ethanol withdrawal

Answer 5

diazepam and chlordiazepoxide (long half life benzo’s)

elderly/liver failure pt = use lorazepam and oxazepam

Question 6

tx alcohol addiction

Answer 6

1) disulfiram: aldehyde dehydrogenase inhibitor
2) naltrexone: opioid antagonist - dec craving
3) acamprosate - NMDA antagonist - prevents relapse
4) topiramate - (not FDA approved). facilitates for GABA fxn, antagonizes glutamate receptor - reduce cravings

Question 7

acamprosate

Answer 7

used to tx alcohol addiction

NMDA blocker

Question 8

topiramate

Answer 8

tx alcohol addiction - not FDA approved

facilitates for GABA fxn, antagonizes glutamate receptor - reduce cravings

Question 9

benzodiazepine - physical dependence or addiction?

Answer 9

addiction is very rare

physical dependence**

Question 10

benzodiazepine withdrawal

Answer 10

LIFE THREATENING

tremor, anxiety, perceptual disturbances, dysphoria, psychosis, sz

Question 11

benzo withdrawal tx

Answer 11

diazepam (replace with long acting) - gradually reduce dose

Question 12

barbituate withdrawal

Answer 12

resemble benzos

Question 13

methylxanthines

Answer 13

caffeine
theophylline
theobromine

Question 14

methylxanthine MOA

Answer 14

block presynaptic adenosine receptors = inc NE release

normally - activation of adenosine receptors inhibit NE release

Question 15

methylxanthine actions by dose

Answer 15

100-200 mg caffeine = inc alertness

1.5 g = anxiety/tremors

2-5 g = stimulation of spinal cord

Question 16

methylxanthine tolerance/withdrawal

Answer 16

rapid tolerance develops

withdrawal: fatigue, sedation

rarely addiction occurs

Question 17

cocaine MOA

Answer 17

inhibits DA, NE, 5 HT reuptake = prolongation of DA effects in limbic system - euphoria

Question 18

cocaine withdrawal

Answer 18

dysphoria, depression, sleepiness, cocaine craving, bradycardia

withdrawal is mild

no tx needed

Question 19

cocaine addiction tx

Answer 19

none show efficacy

Question 20

amphetamines MAO

Answer 20

inc release of catecholamines

weak MAOI

Question 21

amphetamine tolerance/withdrawl

Answer 21

withdrawal: inc appetitie, sleepiness, exhaustion, depression

marked tolerance

Question 22

nicotine MOA

Answer 22

VTA (nicotinic receptors on dopamine neurons) = activation by nicotine stimulates dopamine release

Question 23

nicotine actions - low vs high dose

Answer 23

low: ganglionic stimulation via depolarization - euphoria, relaxation
high: ganglionic blockade - respiratory paralysis, severe hypotension - medullary paralysis

Question 24

nicotine withdrawal

Answer 24

mild

irritable, sleeplessness

extremely addictive

Question 25

tx for nicotine addiction

Answer 25

1) replacement therapy 2) sustained release bupropion 3) varenicline - partial agonist at nicotinic receptors

Question 26

opioids withdrawal

Answer 26

dysphoria lacrimation rhinorrhea yawning

Question 27

opioid withdrawal tx

Answer 27

1) detoxification using opioid agonist (LONG ACTING) - slowly reduce dose - methadone, buprenorphine 2) detox using adrenergic agonist - chronic opioid intake causes withdrawal to cause rebound firing (noradrenergic storm) = clonidine and lofexidine (a2 agonists) 3) detox using opioid antagonists - naltrexone - doesn't satisfy craving or relieve withdrawal = used for pt after detox with high motivation to stay clean

Question 28

marijuana MOA

Answer 28

receptors CB1 (psych effects) and CB2 (on immune cells)

Question 29

marijuana use

Answer 29

drobainol - anorexia associated with weight loss in pt with AIDS and n/v in chemo

Question 30

LSD

Answer 30

5HT2 receptor agonists sympathomimetic effects mydriasis, HTN, tachy, high body temp, flushing, sweating, tremors, piloerection

Question 31

LSD addiction/withdrawal

Answer 31

doesn't cause addiction and there is no withdrawal

Question 32

LSD agitated state tx

Answer 32

diazepam

Question 33

phencyclidine

Answer 33

PCP dissociative anesthetic --> **non-comp antagonist at NMDA receptors** blocks reuptake of NE and DA - -> cholinergic and anticholinergic effects - -> actions at nicotinic and opioid receptors

Question 34

phencyclidine presentation

Answer 34

``` violent bizarre behavior psychosis **nystagmus** miosis ```

Question 35

phencyclidine tx

Answer 35

benzodiazepeines for psychotic behavior and seizures

Question 36

MDMA

Answer 36

empathy and intimacy w/o impairing intellectual capacities release of biogenic amines (mainly 5HT) withdrawal: depression, lasting weeks

Question 37

nitrous oxide

Answer 37

euphoria analgesia --> LOC taken as mixture with O2 (not purely N2O)

Question 38

volatile organic solvents

Answer 38

gasoline, paint thinner, lighter fluid exhilaration, light headedness implicated in cancer, cardiotoxicity, neuropathies, hepatotoxicity

Question 39

organic nitrites

Answer 39

amyl nitrite butyl nitrite used to enhance erection not addictive