Caffeine and Nicotine Flashcards
How much Caffeine does a typical coffee (5 ounce) have?
100mg
What OTC analgesic contains caffeine and how much?
Excedrin, 65mg
What is the distribution of caffeine?
Everywhere.
What is the half-life of caffeine?
Average is 4-5 hours, but can be up to 10 hours in slow-metabolizers.
How is caffeine metabolized?
In the liver, by cytochrome p450.
What can change the activity of cytochrome p450?
Smoking can increase activity. Genetics, age, etc.
How does caffeine work?
It acts as an Adenosine antagonist in the CNS.
What is Adenosine? What kind of actions does it usually have?
A neuromodulator. Adenosine signaling usually results in sedative, depressant and anti-convulsant actions.
How much caffeine is considered a lethal dose?
10 grams.
What does caffeine do to coronary arteries?
It dilates them.
What does caffeine do to cerebral blood vessels?
Constricts them.
What does caffeine do to bronchi?
It relaxes them - you can breathe easier.
What might cause the pain in headaches?
Vasodilation of cerebral blood vessels.
Why does caffeine help some people with headaches?
It vasoconstricts the blood vessels.
Why are people who suffer from migraine headaches generally told to limit caffeine?
Body can become dependent, causing headaches from withdrawal.
How much caffeine can cause tolerance and some withdrawal and craving?
Chronic use (as little as a cup a day).
Is caffeine considered an addictive drug?
No. It isn’t thought that it activates the central reward pathway.
How quickly does Nicotine reach the brain?
7 seconds (smoking).
Where and what is Nicotine broken down by?
In the liver by cytochrome 450 family. 10-20% excreted in urine.
What is the half-life of nicotine?
2 hours.
What is the primary metabolite of nicotine? What is its half-life?
Cotinine. Its half-life is 18 hours.
How does Nicotine work?
It is an agonist at Acetylcholine Nicotinic receptors.
What do Nicotinic Acetylcholine receptors do in the CNS?
They facilitate the release of dopamine, ACh, and glutamate.
Does nicotine active the central reward pathway?
yes.
What affects does nicotine have on the anti-diuretic horomone?
It stimulates production of it.
How does nicotine affect appetite?
It can reduce it.
How does nicotine affect the vomiting center (brain stem) of the brain?
It stimulates it, but you can become tolerant to it.
What do Nicotinic Acetylcholine receptors do in the PNS
Increase in Epinephrine, raises blood pressure may alter taste bud sensitivity.
Does nicotine have a tolerance?
Some.
Does nicotine have dependence?
It has psychological and physical dependence.
What drugs can help people stop smoking?
A nicotine replacement, Bupropion, Varenicline (Chantix).
How does bupropion work?
Blocks the uptake of dopamine (strongly) and norepinephrine and serotonin (weakly). Antagonism of certain nicotinic receptors.
How does bupropion help those trying to stop smoking?
It delays relapse and results in less weight gain.
How does Verenicline (Chantix) work?
Partial agonist at nicotinic ACh receptors. It never activates the receptors fully (unlike nicotine).
How is Verenicline (Chantix) thought to help those trying to stop smoking?
It helps reduce withdrawal symptoms (it can block nicotine from getting to receptor).
How effective was Verenicline (Chantix) in comparison to bupropion and nicotine replacement therapies?
More effective than bupropion, but about the same effectiveness as NRT.
