Caffeine (GOOD)

Overview

Found in tea, coffee, chocolate, and cola (lethal dose is 10g)

Other Info (CNS/ADME)

A: Taken orally, rapidly absorbed. Levels are significant at 30 mins, and peak at 2hr

D: Distributes to all parts of body, and crosses into brain and placenta

M: Genetics determines if metabolism is fast or slow (keeps people up but not all)

E: Half-life from 2.5-10 hours

Method of Administration

Oral

Time of Action

30 mins, significant blood level, but 2 hours at peak

Mechanism of Action

1. Competitive inhibitor at adenosine receptors in brain (GABAergic neurons)

2. Neurons are no loner inhibited, causing dopamine to be released stimulating CNS (cat diagram)

Effects of Short-Term

1. CNS: Mood elevation and reduced fatigue, flow-of-thought

2. Cardiovascular: Construction of blood vessels, increases blood flow/pressure

3. Respiratory: Increase respiratory rate, relax of smooth muscles

Abstainers: Nervousness, psychomotor agitation, bad sleep, tumbling speech/thought

Effects of Long-Term

RINGIR

1. Restlessness

2. Insomnia (Lack of sleep)

3. Nervousness

4. Gastric Upset

5. Increased Urinary Output

6. Rambling Speech/Thought

*No definite link to disease states

Other Effects

1. Caffeine and Smoking: Increased metabolism and lower duration of action, so smokers need to consume more

2. Caffeine and Pregnancy: Decreased metabolism and higher duration of actions, so they consume less. Not teratogenic but slight increase in still birth, miscarriage, and smaller fetus

Misuse Potential

LOW

1. Mild Reinforcer

2. Mild Euphoria

*No link to disease states

Inherent Harmfulness

VERY LOW

Low Dose: No adverse effects

High Dose: Irritability, insomnia, nervousness and weird rhythm

Tolerance

In some individuals

Withdrawal

YES, mild…

1. Headache

2. Fatigue

3. Drowsiness

Addiction

YES, mild addiction

Therapeutic Use

1. Stimulate breathing in preterm newborns