General drugs and cannibis Flashcards Preview

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Flashcards in General drugs and cannibis Deck (26)
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1
Q

What are the general pharmacodynamics of drugs?

A
  • dopaminergic neurones from VTA are stimulated to release DA (reward) into NAcc
2
Q

what are the methods of admin of drugs? how fast are they?

A
  • intranasal (mucous membranes of nasal sinus = slow)
  • oral = very slow
  • inhalational = rapid
  • intravenous = rapid
3
Q

what is the fastest route to the brain? Why?

A
  • inhalation

- pulmonary circuit is very short wherease IV must do systematic circuit before accessing the brain

4
Q

what are the classifications of drugs?

A
  • narcoitics (painkillers): opiate like drugs e.g. Heroin
  • depressants e.g. alcohol, benzodiazepines
  • stimulants e.g. cocaine, amphetamine, caffeine
  • miscellaneous e.g. cannabis, ecstasy (drugs have effects from multiple classes)
5
Q

describe the methods of admin in ascending order of onset of euphoria

A
  • oral
  • intranasal
  • IV
  • inhalational
6
Q

what are cannibis, hashish and hash oil?

A
  • cannabis = plant
  • hasish/resin = trichomes
  • hash oil = solvent extract
7
Q

what does cannabis contain?

A
  • over 400 compounds

- >60 are cannabinoids

8
Q

what do the positives aspects of smoking weed come from?

A
  • from cannabidiol

- balance between cannabidiol vs delta9-THC

9
Q

what is the most potent cannabinoid?

A

delta9-THC

10
Q

how has the dosing of cannabis changed throughout the years?

A
  • in 60’s was 10mg of THC
  • now it is 150-300mg of THC
  • inc. potency
  • delta9-THC and cannabidiol inc.
  • negative effects are more pronounced than positive
11
Q

what are the routes of admin of cannabis?

A
  • oral (5-15% THC delivered): delayed onset, first pass metabolism
  • inhalation (25% THC delivered)
12
Q

why does cannabis slowly accumulate in body?

A
  • very lipid soluble
  • builds up as fattu acid conjugates
  • takes 30 days for effects to cease on body
13
Q

describe the metabolism of cannabis

A
  • liver converts THC –> 11-OH-THC (more potent)
  • GIT excretes 65%
  • much of THC undergoes enterohepatic recycling due to lipid solubility
  • urine excretes 25%
14
Q

describe the plasma conc vs degree of intoxication of cannabis

A
  • THC much more concentrated in brain matter than in blood as very lipid soluble
  • leads to poor correlation b/ plasma cannabinoid conc and degree of intoxication
15
Q

where are the cannabis receptors located?

A

Brain - CB1R (hippocampus, cerebellum, cortex and basal ganglia)
Peripheral: CB2R (immune cells)

16
Q

describe the cannabis receptor

A

inhibitory GPCR linked to AC

17
Q

what is the body’s version of THC?

A

endogenous anadamide

18
Q

describe how cannabis causes euphoria

A
  • stimulation of Gi CB1 receptor
  • inhibits release of GABA
  • disinhibition
  • inc. release of dopamine by inhibiting the inhibition of release of DA
19
Q

describe how cannabis causes psychosis and schizophrenia

A
  • one target is ACC
  • ACC involved in performance monitoring with behavioral adjustment
  • cannabis causes hypoactivity in ACC
20
Q

how does cannabis act to inc. hunger?

A

2 actions on lateral hypothalamus:

  • presynaptic inhibition of GABA –> inc. MCH neuronal activity
  • inc. orexin production
21
Q

how does cannabis cause immunosuppression?

A

depress immune system by agonising CB2Rs on macrophaes, mast cells, B cell, T cell, NK cell

22
Q

what are the general central effects of cannabis?

A
  • psychosis, schizophrenia
  • food intake
  • memory loss (limbic regions)
  • psychomotor performance (cerebral cortex)
23
Q

what are the peripheral effects of cannabis?

A
  • immunosuppressant

- tachycardia/vasodilation via TRPV1 receptors ( not CBRs) –> leads to red eyes as conjuctiva vasodilate

24
Q

why is it impossible to overdose on cannabis?

A
  • medulla has a LOW CB1R expression

- means cardio-resp centre is not affected much

25
Q

when is there an upregulation of CBRs?

A
  • MS/pain/stroke patients (to regulate pain)

- fertility/obesity (pathological and may contribute to obesity/infertility)

26
Q

how do drugs influence levels of delta9-THC?

A
  • autoprotection: dronabinol/nabilone inc. levels and are anti-emetics in cancer, sativex treats MS pain
  • autoimpairment: rimonabant dec. delta9THC, blocks feeling of hunger so anti-obesity