PDA CNS Stim Flashcards
What is the structure of caffeine?
methylxanthinem=, similar to purines
What is hte mechanism of action of caffeine?
competitive antagonist of adenosine receptors produce IPSPs; presynaptic adenosine receptors inhibit glutamate;
caffeine inhibits these inhibitory effects
At higher doses what does caffeine do?
inhibits cAMP phosphodiesterase; results in increase of cAMP
How does caffeine work as a CNS stimulant?
increased alertness
decrease fatigue and drowsiness
can cause nervousness, restlesness and tremors
high doses can stim medullary respiratory and CV centers; can get tachycardia
What are the peripheral effects of caffeine?
positive ionotropic and chronotropic effects
dilates coronary and systemic blood vessels; constricts cerebral blood vessels
diuressis
increase gastric secretion
modest bronchodilation
What are the toxicity and consequences of chronic use?
tolerance, overdose results in excess CNS stim
physical dependence
withdrawal symptoms
What are the sympathomimetic stimulants; act through enhancement of catecholaminergic
amphetamines, cocaine, etc
Mechanism of action of cocaine?
potent inhibitor of the reuptake of norepi, dopamine, and serotonin
binds to transporter itself
increase activity of tyrosine and tryptophan hydroxylases
local anesthetic and vasoconstrictor
Cocaine causes waht in addicts?
profound psychological dependence as well as physical dependence
What is the structure of amphetamine and metamphetamine?
weak bases, absorbed orally, metabolized to benzoic acid
long half life
similar structurally to norepi
What is the mech of action of amphetamine?
relase NE, DA and 5HT
block reuptake of those
partial agonist of alpha receptors
MAO inhibitor at high doses
What are the clinical uses of amphetamine?
tx narcolepsy and ADHD
Side effects of amphetamine?
insomnia, abdominal pain, anorexia, suppression of growth, facial tic, high body temperature
What are the toxic effects of amphetamines and mehtylphenidates?
restlessness, dizziness, tremor psychosis neurtoxicity meth mouth abuse liability
What is the mechanism of action of nicotine?
agonist of nicotinic cholinergic recpetors
neuromuscular junction; initally activates muscle contraction
autonomic ganglia
parasympathetic GI effects
How quickly does tolerance ot nictonie occur?
very rapidly within a few hours
Nicotine withdrawal symptoms include what?
irritability anxiety depression difficulty concentration incresased appetite
What is unique about alcohol?
not potent at all; one dose is about 14 grams
How is alcohol metabolized?
ADH, CYP2E1 and aldehyde dehydrogenase
How many molecules of NADH do you use per consumption of one molecule of ETOH?
2 molecules of NADH
Mixed function oxidase system metabolizes alcohol in who?
chronic alcoholics
What drug blocks aldehyde dehydrogenase?
disulfiram
What are some consequences of alcohl metabolism?
increased NADH, inhibiton of TCA cycle, reduced fatty acid oxidation
increased acetaldehyde
depletion of glutathione
Metabolic changes in alcoholics results in what?
fatty liver
hepatic inflammation
induction of CYP2E1
What are the CNS effects of ethanol?
several ion channels are sensitivie to the presence of ethanol
GABAa receptor-ligand chloride channel
disturbs balance between excitatory and inhibitory
Chronic ethanol liver and GI effects are what?
Hep C often co-morbid steatosis: fatty liver cirrhosis gastritis, pancreatitis, malabsorption chronic diarrhea cancers
Chronic ethanol on CNS system is what?
tolerance occurs; adaptive neruonal changes
Up regulates the excitatory transmission to compensate
both psychological and physical dependence occurs
How frequently does alcohol addiction occur?
5-10% of men and 3-5% of women
What is the neurtoxicity of alchol?
neuralgia memory impairment thiamine deficiency associated with chronic alchol use can produce cerebellar/cerbral atrophy wericke's encephalopathy korsakoffs syndrom
What are the tetraogenic effects?
Associated with chronic maternal alcohol abuse
FAS
What is the general lethal level of ethanol?
400 mg/dl=12 liters
How does one treat alcohol withdrawal?
prevent seizures, deliurium and arrythmias
subsititues for alcohol
