Sadia Hafeez Kazi.
Effect of caffeine on the human body: a review.
Baqai J Health Sci Jan ;18(1):25-30.

Caffeine (1,3,7-trimethylxanthine) is the widely consumed substance all over the world. It is found in coffee, tea, cocoa, etc. Caffeine (CF) is rapidly and completely absorbed from the gastrointestinal tract; peak plasma concentration reaches in about 15 to 120 min after oral ingestion in humans without any significant first-pass effect. There are some drugs which are responsible for the inhibition of metabolism of CF. It also exerts its effect in higher doses on different body organs like neuro, gastrointestinal, renal, respiration, skeletal muscle, cardiovascular systems. Those who are regular consumer of tea, coffee, or CF containing beverages are at the higher risk for the development of CF toxicity which can lead even to death of an individual. The dependence and withdrawal side effects of CF include anxiety, insomnia, restlessness, nervousness, tremors, gastrointestinal upset, tachycardia, psychomotor agitation, etc.

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