Precautions

If caffeine is administered in a kola preparation, kola should always be obtained from a reputable source that observes stringent quality control procedures and industry-accepted good manufacturing practices. Consumers should look for the designations "U.S.P." (U.S. Pharmacopeia) or "NF" (National Formulary) on kola nut labeling. Herbal preparations prepared under USP or NF guidelines meet nationally recognized strength, quality, purity, packaging, and labeling standards as recommended by the United States Food and Drug Administration (FDA).

CAFFEINE CONTENT OF COMMON DIETARY AND MEDICINAL SOURCES
Source	Standard amount in milligrams (mg)
Bottled beverages (12 oz)
Red bull	115.5
Jolt	72
Mountain Dew	55
Diet Coke	45
Dr. Pepper	41
Coca Cola Classic	34
Coffee (8 oz)
Brewed	80–135
Instant	65–100
Decaf brew	3–4
Tea (8 oz)
Iced	47
Brewed	40–60
Instant	30
Green	15
Chocolate
Hot cocoa (8 oz)	14
Chocolate milk (6 oz)	4
Chocolate bar (1 oz)	3–6
Medications (per tablet)
Vivarin	200
No-Doz	100
Midol, Maximum Strength	65
Anacin	32
Dristan	30

Avoid taking too much caffeine when it is being taken as an over-the-counter drug. Consider how much caffeine is being taken in from coffee, tea, chocolate, soft drinks, and other foods that contain caffeine. Check with a pharmacist or healthcare professional to find out how much caffeine is safe to use.

Caffeine cannot replace sleep and should not be used regularly to stay awake as the drug can lead to more serious sleep disorders, like insomnia.

People who use large amounts of caffeine over long periods build up a tolerance to it. When that happens, they have to use more and more caffeine to get the same effects. Heavy caffeine use can also lead to dependence. If an individual stops using caffeine abruptly, withdrawal symptoms may occur, including headache, fatigue, drowsiness, yawning, irritability, restlessness, vomiting, or runny nose. These symptoms can go on for as long as a week. In addition, caffeine dependence is not confined to the adult population. A study published in 2002 found that American teenagers have a high rate of caffeine dependence, partly because they consume large amounts of carbonated beverages that contain caffeine.

If taken too close to bedtime, caffeine can interfere with sleep. Even if it does not prevent a person from falling asleep, it may disturb sleep during the night.

The notion that caffeine helps people sober up after drinking too much alcohol is a myth. In fact, using caffeine and alcohol together is not a good idea. The combination can lead to an upset stomach, nausea, and vomiting.

Older people may be more sensitive to caffeine and thus more likely to have certain side effects, such as irritability, nervousness, anxiety, and sleep problems. Recent findings also suggest that people with insulin-dependent diabetes should monitor their caffeine intake. One study published in 2002 found that caffeine appears to decrease insulin sensitivity by about 15%

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Example

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Caffeine Effects

The following effects are commonly attributed to over-use of caffeine - while reading them bear in mind that what is true for one person may not be true for someone else:

1. Stimulates your heart, respiratory system, and central nervous system.

2. Makes your blood more `sludgy' by raising the level of fatty acids in the blood.

3. Causes messages to be passed along your nervous system more quickly

4. Stimulates blood circulation

5. Raises blood pressure

6. Causes your stomach to produce more acid

7. Irritates the stomach lining

8. Makes digestion less effective by relaxing the muscles of your intestinal system

9. Its diuretic effect caused increased urination - although you would have have to drink about 8 coups of coffee in one sitting for this to occur ⁽¹⁾

10. Stimulates the cortex of your brain heightening the intensity of mental activity. This can result in a temporary feeling of alertness and, in the short term, banishes drowsiness and feelings of fatigue. In those who already have high levels of anxiety the heightened intensity of mental activity can produce unpleasant effects. But check out ⁽²⁾ below which contradicts this.

11. Affects the length and quality of sleep. Heavy caffeine users suffer from sleep-deprivation because their nervous system is too stimulated to allow them deep, restful or prolonged sleep.

12. The American Medical Journal has reported a correlation between caffeine and decreased bone density or osteoporosis in women.

In addition to the above effects prolonged or very heavy caffeine use can produce the following:

13. `Caffeine nerves' a jittery feeling with shaking hands, palpitations, and wobbliness in the legs.

14. Caffeine addiction which involves nervousness, irritability, agitation, headaches or ringing in the ears.

15. Causes your adrenal glands to release their hormones into your bloodstream

16. Causes blood sugar, or blood glucose, to be released from storage through the effects of the adrenal hormones. This gives you a temporary lift but…

17. …requires your pancreas to over-work. This is because your pancreas now has to produce extra insulin to reduce this extra blood sugar. Once the extra insulin has 'mopped up' the extra blood sugar your temporary lift from the caffeine ends. Your vitality level is back to normal. However in heavy caffeine users the pancreas, in time, becomes over-sensitive and over-zealous. Now it begins producing too much insulin – it 'mops up' not just the excess blood sugar but the blood sugar you need to feel alert and energetic. The initial effect of this is a let-down effect and a craving for more caffeine to give you a further boost. A later effect can be excessive and chronic tiredness, even on waking in the morning. Some people find that many of the psychological complaints common to reactive hypoglycaemia (the emotional yo-yo effect, shakiness, palpitations, weakness, tiredness, etc.) disappear within a few days of stopping caffeine.

NOTE: The fact that caffeine can produce these sensations and symptoms does not mean that it is the 'only' cause of such symptoms. But if you experience similar symptoms and your medical advisor confirms that they do not have a verifiable organic cause then you may wish to cut out caffeine for a few weeks to see if the symptoms reduce or disappear.

On the other hand...

... some research indicates that caffeine in coffee (though not cola) can be beneficial in preventing heart disease ⁽¹⁾ - or, at least, that coffee drinkers had a lowered incidence of heart disease. Nevertheless they were unable to confirm that one caused the other nor why this apparent relationship might be appearing.

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