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14 Cards in this Set
- Front
- Back
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What is the most dangerous dependence-producing drug?
which receptor has the highest sensitivity to nicotine? Where is this the most prevalent? Are other forms prevalent there as well? |
Nicotine
a4B2; CNS Yes, this is one of the reasons for the complexity of nicotine's actions. |
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What are the differences b/t the effects of Ach and those of Nicotine at the Cholinergic receptor?
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ACh opens the nicotinic receptor for a short period of time, due to a series of conformational changes that produces a desensitized state. During this stage, the receptor b/ with ^ affinity, but remains closed to ions and inactive.
Nicotine enters the CNS more easily, and *is not* metabolized by ACh-esterase. |
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Can low concentrations of nicotinic receptor agonists push the receptor into a desensitized state w/o first activating?
Is nicotine readily absorbed from the GI tract? lungs? buccal membrane? Skin? When smoking, which lvls are higher: venous nicotine or CNS nicotine? |
Yes, this can happen.
- all of them except GI tract. - CNS, by 5x |
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Nicotine's effects on the Peripheral NS:
- predictable? - activating or paralysing of the sympth? Parasympth? CNS effects: - stimulate or depress? - does it induce vomiting by central actions? peripheral? - Are most nicotinic receptors in the CNS prejunctional or postjunctional? + result? What metabolizes nicotine? |
- no.
- can do either for both. - stimulate - both - post-junctional + stim and pleasure/reward action of the drug result from effects on release of other nt's across the junction (dopamine & excitatory amino acids) - CYP2A6; hl = 2hrs. |
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What is our goal in drug development?
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development of a nicotinic receptor antagonist that blocks addictive action of nicotine WITHOUT blocking cholinergic neurotransmission in the autonomic and somatic nervous systems
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lung disease, atherosclerosis, coronary artery disease, aggravation of hypertension, delayed wound healing, cancer
... all are what type of effects? |
chronic effects of smoking.
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Acute effects of Nicotine:
- skel mus stim? relax? - vaso___ in most beds? skel musc beds? |
- relax b/c of desensitization
- constriction in most beds, dilation in skel-mus beds. |
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Is toleranace a normal biological phenomenon? How about physical dependence? Withdrawal?
Describe these three. |
All are normal biological phenomena.
Tolerance: takes more drug to get same effect Phy dependence: resetting of homeostatic mechanisms i/response to drug presence Withdrawal syndrome: sx that appear upon cessation of drug that has caused dependence |
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In which (gross) area of the brain is nicotine having its addictive effect?
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Probably the midbrain ventral tegmental area (VTA).
Glutamate secreting neurons regulate dopamine secreting neurons, and nicotinic receptors are on both of these in the VTA. |
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What are some pharmalogical interventions for nicotine withdrawal Sx? Contraindications? Effect on Quit rates?
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NRT: those with recent MI or HTN
- raises 1y abstinence from 10 to 20% Bupropion (Zyban, Wellbutrin) - doubles quit rates. |
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What is the mech of action for bupropion?
Does nortryptilene work too? clonidine? How about other antidepressants? |
"atypical" catecholamine/5HG reuptake inhibitor
- increases dopamine lvls in nucleus accumbens (like nicotine!) - might also block a4B2 receptors Yes, it does. Yes. No, they don't. |
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What is CHANTIX?
- mech? - admin? |
varenicline
- high affinity, pretty specific partial agonist of a4B2 receptor --> blocks action of nicotine (full agonist) b/c varenicline has such a high affinity - orally admin'ed prior to and during quit period. |
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What is Rimonabant?
- mech? - effect on quitting? - FDA approved? |
CB1 receptor antagonist
- blocks nicotine-induced elevation of dopamine lvls in the nucleus accumbens of rodents. - seems to increase cessation rates 2-fold - not yet. |
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What are the "black box" SEs of bupropion and varenicline?
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depression, suicidal thoughts, suicidal actions.
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