caffeine Flashcards
Methyxanthines
Theophylline
Theobromine
Sources of Caffeine
Coffee Tea Chocolate Soda Drug preperations
sources of Theophylline
Tea
Sources of Theobromine
Chocolate
Caffeine content in various sources
Coffee (5 oz) 100 mg Tea ( 5 oz ) 50 mg Soda (12 oz) 40 mg Chocolate (Bar) 10 mg Medications variable
Mechanisms of Action
Blockade of adenosine receptors (low doses)
inhibition of phosphodiesterase (high doses)
Blockade of GABA A receptors (high doses)
Increased calcium release (Very high doses)
Methylxanthines and Adenosine A 2 receptors
at low doses, Methylxanthines block Adenosine A2a receptors
Minor inhibitory transmitter
A2a receptors are blocked by Methylxanthines causing mild disinhibition of the Brain
Acute Cognitive and Behavioral effects of caffeine
Arousal
Alertness
Wakefulness
Increased Energy
Increased concentration
Improved Reaction
Increased Dexterity
Acute physiological effects of caffeine
- decreased blood flow to brain
- Increased incidence of migraine headaches
- Decreased incidence of migraine headaches
- Increased respiration rate
- Dilated airways
- Increased gastric secretions
- Diureses
Caffeine toxic effects
500 - 1000 mg
Anxiety Irritability Insomnia Fever Flushing
Caffeine toxic effects
>1000 mg
Paranoia
Delusions
Hallucinations
Stereotypes
Therapeutic uses of Methylxanthines
Headache
Asthma
Narcolepsy
Sleep Apnea
Caffeine tolerance
cellular tolerance
Behavioral tolerance
contextual tolerance
Caffeine Cellular Tolerance
Increase in Adenosine receptors
Caffeine Behavioral Tolerance
Functioning in Presence of Drug
Caffeine Contextual Tolerance
Context in which drug is taken
Induces tolerance
Caffeine physical dependence
Headache
Fatigue
Craving
Caffeine Psychologicl Dependence
Weak Reinforcer
Increases release of dopamine in cortex
Caffeine Health Risks?
Cancers Benign Breast Disease Reporduction Cardiovascular Anxiety Disorders Caffeinism Physical Dependence
Caffeine Health Risks?
Cancers
no clear association
Caffeine Health Risks?
Benign breast Disease
Increases sensitivity
Caffeine Health Risks?
Reproduction
Fertility, miscarriage, growth
Caffeine Health Risks?
Cardiovascular
tachycardia, arrythmia
Caffeine Health Risks?
Anxiety Disorders
Precipitates panic attacks
Caffeine Health Risks?
Caffeinism
Agitation, Mood changes
Caffeine Health Risks?
physical dependence
withdrawal effects
Caffeine use and disease
associated with LOWER risk of diseases
- Diabetes (type 2)
- Cardiovascular
- Liver Disease
- Parkinsons Disease
*Coffee contains anti-oxidants that are anti-inflammatory
low to moderate caffeine consumption
recommended
<= 3 cups per day
