Caffeine Flashcards
Define Caffeine
mild psychostimulant
belongs to class of chemicals called methylxanthines
When was the first recorded history of caffeine
1000 AD in an Arabian medical bool
How is caffeine absorbed
absorbed easily via the digestive system due to its high lipid solubility
what is the timeline of caffeine
reaches the organs in five minutes, peaks in blood in thirty, maximal CNS effect in two hours
How is coffee metabolized
liver (smokers metabolizer faster)
how is caffeine excreted
90% excreted as active/inactive metabolites
what is the result of caffeine metabolism
psychoactive metabolites (xanthines)
what are some psychoactive xanthines
theophylline (used for asthma)
theobromine (found in chocolate)
what are the psychological effects of caffeine in a moderate dose
mood elevation
enhance thought process
reduced fatigue
improves auditory vigilance and visual reaction time
increased capacity for muscular work and sustained intellectual task performance
what are the psychological effects of caffeine at high doses
insomnia
restlessness
mild sensory disturbances
muscle tenseness
anxiety/panic attacks in susceptible individuals
what is the difference between caffeine and other psychostimulants in moderate doses
effects on blood pressure and heart rate are inconsistent i.e. caffeine does not always raise blood pressure
what are the physical effects of caffeine at moderate doses
vasoconstrictor indirectly on the ANS (increased HR and BP)
Direct on heart for vasodilation
dilates bronchial tubes
what is caffeine toxicity
lethal doses lead to convulsions and respiratory arrest
what are the pharmacodynamics of caffeine
Adenosine receptor antagonist
blocking adenosine receptors increases neuronal activity (primarily of norepinephrine and glutamate)
AGONIST of transmitter release
what is adenosine
neuromodulator that normally slows down neuronal activity in the CNS and PNS
