A stimulant found naturally in coffee beans, tea leaves, cocoa
beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines.
A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes
has 40-100 milligrams. Green tea has one-third as much caffeine as black tea.
Caffeine is an alkaloid. It is metabolized in the liver and the breakdown products
of caffeine are excreted through the kidney. In women on oral contraceptives, the
rate at which they clear caffeine from the body is considerably slower. Pregnancy
reduces a woman's ability to process caffeine still further. The half life of caffeine
in an adult is about 3 to 4 hours. In pregnancy, it is 18 hours.
In doses of 100-200 mg. caffeine can increase alertness, relieve drowsiness and
improve thinking. At doses of 250-700 mg/day, caffeine can cause anxiety, insomnia,
nervousness, hypertension, and insomnia. Caffeine is a diuretic and increases urination.
It can curiously enough make it more difficult to lose weight because it stimulates
insulin secretion, which reduces serum glucose, which increases hunger.
Caffeine can help relieve some headaches, so a number of over-the-counter and
prescription pain relievers include it as an ingredient, usually with aspirin or
another analgesic.
The word "caffeine" came from the German Kaffee and the French café meaning,
of course, coffee.
medical
dictionary, online medical dictionary, medical
terminology dictionary, free online medical
dictionary, medical dictionary, online medical
dictionary, medical terminology dictionary, free
online medical dictionary, dictionary medical,
dictionary medical online, dictionary medical
terminology, dictionary free medical online,
dictionary free medical, dictionary medical
terms, dictionary drug medical medicine,
dictionary health illustrated medical nursing
profession stedmans, dictionary English medical,
dictionary medical online terminology,
dictionary encyclopedia medical online,
condition dictionary medical, dictionary
medical, dictionary drug medical, medical
dictionary software, cyclopedic dictionary index
medical tabers thumb, medical dictionary, online
medical dictionary, medical terminology
dictionary
