Physiologic and psychotropic effects of caffeine on man. A review.

Caffeine, in substantive amounts, is frequently taken by the clinical or hospitalized patient. Caffeine content of coffees, teas, cola drinks, cocoa, and drugs is summarized. Systems and organs affected by caffeine include the central nervous system, the cardiac muscle, the kidney, the gastric mucosa, and smooth muscle. Psychotropic and sleep response varies with age and degree of habituation. Symptoms of caffeinism, caffeine withdrawal, and caffeine-drug interactions are described.