Caffeine, nicotine and alcohol are probably the three
most widely used psychoactive chemical agents in the
world. Caffeine is generally used as a beverage in coffee,
tea and soda pop drinks. It is non-prescription drug
where per capita intake for the entire world's population
approximates 70 mg a day, but in the United States that
figure exceeds 200 mg. and four out of five adult Americans
report regular intake.
Caffeine's use apparently dates back thousands of years
- tea in China to 5000 years ago, Coffee beans in Africa
to 1500 years ago, Coffee in Arabia to 800 years ago.
Pharmacologically, caffeine belongs to a brain stimulant
group of alkaloids called methylxanthines (also called
xanthines). Theophylline and Theobromine are also Xanthines.
It occurs naturally in some plants nuts, seeds or leaves.
e.g. Coffee from the Coffea arabica plant;
soft drinks, like Cola drinks, made from Kola nuts
( but less than 5% of the caffeine is from the kola
nut; the other 95% uses the decaffeination extract process
tea leaves from Thea sinensis.
Cocoa is from the seeds of the Theobroma cocoa plant
(or cocoa beans) and is used to make chocolate, chocolate
milk, hot cocoa, and various other candies. This contains
mainly theobromine. A candy bar (3.5 ounces) may contain
caffeine (e.g. 12 mg) and theobromine (e.g. 155 mg)
and a 5 ounce hot cocoa cup, 10 mg caffeine and 200
1. Food additive :This is regulated by the Federal Food
and Drug Administration (FDA) with a label insert when
caffeine has been added.
2. Natural usage of Caffeine need not be on the label.e.g.
coffee, tea, soft drinks, chocolate candy bars
3. Over-the-counter and prescription medications e.g.
stimulants with antimigraine or antihistamine drugs,
cold remedies, and pain killers. Use relates to management
of side-effects or symptoms of fatigue and hyperactivity
Biological effects of caffeine in animals and man depend
on the dose, method of administration and duration of
Technically, caffeine enhances CNS norepinephrine secretion,
inhibits phosphodiesterase breakdown of cyclic 3',5'-adenosine
monophosphate (cAMP) at high concentrations, sensitizes
central catecholamine postsynaptic receptors (including
those for dopamine), enhances cyclic guanosine 3',5'-monophosphate
(cGMP), and modulates acetylcholine and serotonin activity.
Caffeine induces significant increases in cortisol,
but no meaningful change in prolactin.
Caffeine's ability to antagonize adenosine receptors
in the brain probably accounts for the most important
of the drug's behavioral effects. Adenosine is an important
CNS neuromodulator, possessing sedative, anxiolytic,
and anticonvulsant properties. Adenosine also dilates
blood vessels in cerebral and coronary circulatory networks.
Caffeine competes with adenosine for binding at its
high-affinity receptor sites, preventing adenosine's
normal tranquilizing or sedating effects. Thus, caffeine's
stimulant or anxiety-inducing actions appear to be secondary
effects of adenosine antagonism. Chronic caffeine exposure
has also been shown to induce heterologous up-regulation
of adenosine receptors in humans. Caffeine's antagonism
to vasodilation by adenosine may account for caffeine
withdrawal headaches, as well as for its efficacy in
treating migraine headaches.
Positron emission tomography (PET) imaging studies
confirm that a caffeine dose of 200 mg produces a diffusely
decreases cerebral blood flow by about a third within
an hour of administration
Caffeine is a mild stimulant and people have variable
sensitivity to caffeine. Caffeine does not accumulate
in the blood and is normally excreted within several
hours. It can speed reaction time, prolong vigilance
but will not help people "sober up" to too
Caffeine is the single most important cause of anxiety
in our society and doses like 1000 mg per day is
anxiety evoking in almost everyone and many are exquisitely
sensitive e.g. 50 mg or 100 mg. This may lead to misdiagnoses
of Panic or Generalized Anxiety Disorder. Caffeine may
impair sleep in sensitive individuals and is not advised
at night in insomniacs.
In addition to other psychiatric or medical conditions,
concomitant use of other psychoactive agents, such as
nicotine, alcohol, or benzodiazepines, is common in
caffeine users. This often confounds an accurate diagnosis.
Caffeine is, at this point, regarded as safe for long
term use in regard to its physical effects:
* May 1987, FDA "studies on teratology, reproduction
behavior, carcinogenicity, and cardiovascular disease...found
no evidence to show that the use of caffeine in carbonated
beverages would render these beverages injurious to
* 1984 AMA Council on Scientific Affairs "Moderate
tea or coffee drinkers probably need have no concern
for their health relative to their caffeine consumption
provided other lifestyle habits (diet, alcohol consumption)
are moderate, as well."
Available information does not suggest a recommendation
against the moderate use of coffee unless it is known
to cause specific symptoms, like anxiety, agitation
or palpitations, in the individual using it. There is
no indication that caffeine, a natural component of
both coffee and tea, is a risk factor in human cancer.
Coffee, tea and other caffeinated beverages do not
cause any persistent increase in blood pressure.though
some individuals may experience a small, short-lived
rise in blood pressure usually not lasting more than
Most scientific research does not support a link between
caffeine consumption and cardiovasculardisease - weak
and inconsistent evidence or 1989 Framingham Heart Study
"no deleterious or salutary effect of coffee consumption."
1990 Harvard University study: Caffeine intake does
not appreciably increase the risk of coronary heart
disease or stroke. Individual patients may find the
frequency or severity of cardiac arrhythmias increasing,
but generally not.
Three major studies involving more than 15,000 women
have found no birth defects associated with caffeine
consumption. Even offspring of the heaviest coffee drinkers
were not found to be at higher risk of birth defects,
spontaneous abortion or preterm delivery, or dysmaturity.
The most recent FDA animal studies have found no birth
defects when rats are given high doses of caffeine in
their drinking water. These results contradict earlier
FDA research in 1980 that had triggered an advisory
to pregnant women to avoid caffeine involving force-fed
rats high doses of caffeine all at once through stomach
Caffeine may adversely affect reproduction in humans
, but variables in like exercise level, dietary habits,
stress, were not controlled.
Children are no more sensitive to caffeine's potential
effects than adults and it may be eliminated from the
body twice as rapidly in children than adults.
Caffeine consumption patterns differ somewhat from
drugs of dependence.
1. It does not result in steadily increased doses over
short periods. However, caffeine use generally increases
gradually over the years). Consumption often surges
during college years, for both social reasons and for
enhancing alertness and opposing sleep.
2. Caffeine withdrawal headaches (tapering by half
cup per day may diminish) occur but generally one can
get off it. Also irritability and anxiety may occur.
Theophylline pharmacologically is a beta adrenergic
stimulant: it is commonly used in asthma as a bronchodilator,
and sometimes in congestive heart failure in very high
doses (500-750 mg). This can have potentially cause
marked stimulation: tea contains a fraction of this
CAFFEINE CONTENT OF VARIOUS DRINKS:
PERSPECTIVE: : Amounts in common drinks.
Coffee contains Caffeine alone e.g. 100 mg
Tea contains Caffeine e.g. 40mg , Theophylline e.g.
1 mg of theophylline (less potent stimulant than caffeine)
and Theobromine which is a far less potent stimulant
but may have diuretic effects.
A soft cola or pop drink contains e.g. 50 mg Caffeine
(12 ounce not 5 ounce like tea or coffee cups) and of
course no Cocaine.
Effects are additive: a cup of coffee plus 2 cups of
tea and an over the counter preparation together may
produce toxic effects.
The caffeine content of an average cup of coffee (5
ounce ) is actually variable : range 40 mg -150 mg,
of tea range 20-ll0 mg, of soda pops 30 mg to 60 mg
Dosage of caffeine in coffee depends on coffee bean
, origin (geography, soil, growing season length), harvest,
degree of fine grinding, brew length and method.
Similarly, dosage of caffeine of tea will depend upon
the type of tea used, the tea leaf cut, and how long
it was brewed.
Dosage of caffeine in soda pops will depend mainly
upon the decaffeination extraction process from which
it was derived and also on the Kola nut (slight). Soft
drinks containing caffeine will show it as an ingredient
on the product label and the level of caffeine in a
particular brand is consistent from can to can because
of strict manufacturing controls.
USING A 5 OUNCE CUP SIZE: some guidelines
Coffee via drip method, with fine ground, in machines
Percolated coffee 64-124 mg.
Instant coffee 40-108 mg.
Tea 1 min. brew 9 mg -33 mg
5 min. brew 20 mg -50 mg
Instant tea 12 mg -28 mg
Percolated Decaffeinated coffee 2-5 mg
Instant Decaffeinated coffee 2 mg
Decaffeinated soft drinks 0 mg to 0.09mg (virtually
(Consumers' Union, FDA, National Coffee Association
of the U.S.A., and National Confectioner's Association
of the U.S., www. /net-abuse.org/~lizardo/caff.sources.html)
12 0UNCE DRINKS:
Iced tea 22-36 mg
Soft drinks vary greatly:
Jolt 72.0 mg
Sugar-Free Mr. Pibb 58.8 mg
Mountain Dew 54.0 mg
Mello Yello 52.8 mg
TAB 46.8 mg
Coca-Cola 45.6 mg
Diet Coke 45.6 mg
Shasta Cola 44.4 mg
Shasta Cherry Cola 44.4 mg
Shasta Diet Cola 44.4 mg
Shasta Diet Cherry Cola 44.4 mg
Mr. PIBB 40.8 mg
Dr. Pepper 39.6 mg
Big Red 38.4 mg
Sugar-Free Dr. Pepper 39.6 mg
Pepsi-Cola 38.4 mg
Aspen 36.0 mg
Diet Pepsi 36.0 mg
Pepsi Light 36.0 mg
RC Cola 36.0 mg
Diet Rite 36.0 mg
Kick 31.2 mg
Canada Dry Jamaica Cola 30.0 mg
Canada Dry Diet Cola 1.2 mg
[National Soft Drink Association , www. net-abuse.org/~lizardo/caff.sources.html]
THE PROCESS OF DECAFFEINATION
Two basic decaffeination processes are used in the
1. water extraction :
a. coffee beans are steamed and then soaked and then
b. caffeine diffuses from the beans into the water,
v. uses no artificial chemicals.
2. direct solvent extraction:
a. direct application of methylene chloride, ethyl
acetate or carbon dioxide to the coffee beans
b . coffee beans are then steamed to remove the residual
solvent, then dried and roasted.
Methylene chloride may when inhaled be an animal carcinogen
but to mice in drinking water was not.
The FDA regards its potential health risk as so low
"as to be essentially non-existent" (FDA,
OVER-THE-COUNTER MEDICATIONS (FDA regulated; based
NoDoz tablets 100
Vivarin tablets 200
Excedrin P.M. 0
[FDA's Center for Drugs and Biologics; www. net-abuse.org/~lizardo/caff.sources.html]
Sources above include the following websites:
Barone J J, Roberts H: Human consumption of caffeine.
In Caffeine, P B Dews, editor, p 59. Springer-Verlag,
New York, 1984.
Benowitz N L: Clinical pharmacology of caffeine. Ann
Rev Med 41: 277, 1990.
Benton D : Caffeine: use and abuse . Nurs Stand
1989 ; 44 (3 ): 34-6 .
Bruce MS , Lader, M : Caffeine abstention in the management
of anxiety disorders . Psychol Med 19 (1 ): 211-4,
Cameron O G, Modell J G, Hariharan M: Caffeine and
human cerebral blood flow: A positron emission study.
Life Sci 47: 1141, 1990.
Carroll ME, Hagen, EW, Asencio, M , Brauer, LH : Behavioral
dependence on caffeine and phencyclidine in rhesus monkeys:
interactive effects . Pharmacol Biochem Behav
31 (4 ): 927-32, 1988.
Charney D S, Heninger G R, Jatlow P I: Increased anxiogenic
effects of caffeine in panic disorder. Arch Gen Psychiatry
42: 233, 1985.
Clementz GL , Dailey, JW : Psychotropic effects of
caffeine . Am Fam Physician 37 (5 ): 167-72,
Conlay LA, Evoniuk, G , Wurtman, RJ : Endogenous adenosine
and hemorrhagic shock: effects of caffeine administration
or caffeine withdrawal . Proc Natl Acad Sci U S A
85 (12 ): 4483-5, 1988.
Couturier E G, Hering R, Steiner T J: Weekend attacks
in migraine patients: Caused by caffeine withdrawal?
Cephalalgia 12: 99, 1992.
Diener HC, Dichgans, J, Scholz, E, Geiselhart, S, Gerber,
WD , Bille, A : Analgesic-induced chronic headache:
long-term results of withdrawal therapy . J Neurol
236 (1 ): 9-14 , 1989.
Dunbar GC, Morgan, DD , Perera, KM : The concurrent
use of alcohol, cigarettes and caffeine in British benzodiazepine
users as measured by a general population survey . Br
J Addict 83 (6 ): 689-94, 1988.
Fennelly M, Galletly D C, Purdie G I: Is caffeine withdrawal
the mechanism of postoperative headache? Anesth Analg
72: 449, 1991.
Goldstein A, Kaizer S, Whitby O: Psychotropic effects
of caffeine in man. IV. Quantitative and qualitative
differences associated with habituation to caffeine.
Clin Pharmacol Ther 10: 489, 1969.
Graham K : Reasons for consumption and heavy caffeine
use: generalization of a model based on alcohol research
. Addict Behav 13 (2 ): 209-14, 1988.
Greden J F: Anxiety and depression associated with
caffeinism among psychiatric inpatients. Am J Psychiatry
135: 963, 1978.
Greden, JF , Pomerleau, O. Caffeine-Related Disorders
And Nicotine-Related Disorders - in Comprehensive Textbook
of Psychiatry Sixth Edition. Williams and Wilkins. Baltimore.
Griffiths R R, Bigelow G E, Liebson I A: Human coffee
drinking: Reinforcing and physical dependence producing
effects of caffeine. J Pharmacol Exp Ther 239: 416,
Griffiths RR , Woodson, PP : Caffeine physical dependence:
a review of human and laboratory animal studies . Psychopharmacology
(Berlin) 94 (4 ): 437-51, 1988.
Griffiths RR, Bigelow, GE , Liebson, IA : Reinforcing
effects of caffeine in coffee and capsules . J Exp
Anal Behav 52 (2 ): 127-40, 1989.
Griffiths R R, Evans S M, Heishman S J, Preston K L,
Sannerud C A, Wolf B, Woodson P P: Low-dose caffeine
physical dependence in humans. J Pharmacol Exp Ther
255: 1123, 1990.
Hughes J R, Higgins S T, Bickel W K: Caffeine self-administration,
withdrawal, and adverse effects among coffee drinkers.
Arch Gen Psychiatry 48: 611, 1991.
Hughes J R, Oliveto A H, Helzer J E, Higgins S T, Bickel
W K: Should caffeine abuse, dependence, or withdrawal
be added to DSM-IV and ICD-10? Am J Psychiatry 149:
James JE, Paull, I, Cameron, TE, Miners, JO , Birkett,
DJ : Biochemical validation of self-reported caffeine
consumption during caffeine fading . J Behav Med
11 (1 ): 15-30, 1988.
Johnson GD, Fatis, M, Sonnek, D , Shawchuck, C : A
survey of caffeine use and associated side effects in
a college population . J Drug Educ 18 (3 ): 211-20,
Kirmer DA : Caffeine use and abuse in psychiatric clients
. J Psychosoc Nurs Ment Health Serv 26 (11 ):
20-5 , 1988.
Koczapski A, Paredes, J, Kogan, C, Ledwidge, B , Higenbottam,
J : Effects of caffeine on behavior of schizophrenic
inpatients . Schizophr Bull 15 (2 ): 339-44 ,
Kuribara H, Tadokoro S: Caffeine does not effectively
ameliorate, but rather may worsen the ethanol intoxication
when assessed by discrete avoidance in mice. Jpn J Pharmacol
59: 393, 1992.
Lee MA, Flegel, P, Greden, JF , Cameron, OG : Anxiogenic
effects of caffeine on panic and depressed patients
. Am J Psychiatry 145 (5 ): 632-5, 1988.
Lee MA, Flegel, P, Cameron, OG , Greden, JF : Chronic
caffeine consumption and the dexamethasone suppression
test in depression . Psychiatry Res 24 (1 ):
61-5 , 1988.
Levinson H C, Bick E C: Psychopharmacology of caffeine.
In Psychopharmacology in the Practice of Medicine, M
D Jarvik, editor, p 451. Appelton-Century-Crofts, New
McGowan JD, Altman, RE , Kanto, WJ : Neonatal withdrawal
symptoms after chronic maternal ingestion of caffeine
. South Med J 81 (9 ): 1092-4, 1988.
Paul S, Kurunwune B, Biaggioni I; Caffeine withdrawal:
Apparent heterologous sensitization to adenosine and
prostacyclin actions in human platelets. J Pharmacol
Exp Ther 267: 838, 1993.
Russ NW, Sturgis, ET, Malcolm, RJ , Williams, L : Abuse
of caffeine in substance abusers [letter] . J Clin
Psychiatry 49 (11 ), 1988.
Silverman K, Evans S M, Strain E C, Griffiths R R:
Withdrawal syndrome after the double-blind cessation
of caffeine consumption. N Engl J Med 327: 1109, 1992.
Snyder S H, Katims J J, Annau Z, Bruns R F, Daly J
W: Adenosine receptors and behavioral actions of methylxanthines.
Proc Natl Acad Sci USA 78: 3260, 1981.
Stein MB , Uhde, TW : Depersonalization disorder: effects
of caffeine and response to pharmacotherapy . Biol
Psychiatry; 26 (3 ): 315-20, 1989
Stern KN, Chait, LD , Johanson, CE : Reinforcing and
subjective effects of caffeine in normal human volunteers
. Psychopharmacology (Berlin) 98 (1 ): 81, 1989.
Winstead D K: Coffee consumption among psychiatric
inpatients. Am J Psychiatry, 133: 1447, 1976.