Caffeine is a psychoactive stimulant isolated from the coffee beans. This compound is found in beans, leaves and fruits of various plants where it acts as a natural pesticide. Caffeine in plants protects the herb from insects feeding on the plants, by paralyzing or killing them. Humans usually use caffeine extracted from the bean of the coffee plant. In humans, caffeine stimulates the central nervous system, providing the temporary relief from the sleepiness and restoring alertness. Moreover, caffeine is the most widely consumed psychoactive substance, and it is legal all over the world.
Overuse and intoxication
Caffeine is an antagonist of the central nervous system’s receptors for the neurotransmitter adenosine. This way, the bodies of people who regularly consume caffeine gradually become dependent on the continuous presence of the substance, while increasing the number of the adenosine receptors in the central nervous system. Caffeine tolerance develops very quickly, especially if the person consumes a lot of coffee on a regular basis. Scientists have discovered that the complete tolerance develops after consuming 300 mg 3 times per day for 18 days, in many cases even earlier.
Symptoms of overdose
Consuming large amounts of coffee over long periods of time can provoke a condition known under the name caffeinism. This condition is characterized by physical dependency and various unpleasant symptoms such as nervousness, insomnia, heart palpitations and similar. Caffeine overdose is the intoxication by large amounts of caffeine, which results in overstimulation of the central nervous system. Symptoms include restlessness, excitement, euphoria, rapid and irregular heartbeats, ringing in the ears, seizures and twitching in muscles, problems with vision, rapid breathing, abdominal pain, vomiting, dehydration, fever, headache, delusion and general confusion. Symptoms vary depending on the amount of ingested caffeine by the kilogram of the body mass, and in most severe cases overdose can result in death. Lethal dose of caffeine for humans is somewhere around 150 to 200 milligrams per kilogram of the body mass. This is a rough equivalent for 80 to 100 cups of coffee taken by an average individual. Achieving lethal dose with regular coffee is thus extremely difficult, but serious cases of caffeine intoxication have been reported from overdosing on caffeine pills.
Treatment for caffeine overdose
Treatment for caffeine intoxication is mainly supportive and focused on treatment of immediate symptoms. Do not force the person to throw up unless told to do so by a doctor. Patients should receive immediate medical attention as their vital signs need to be measured. Doctors will usually administer activated charcoal, or laxatives, to get the caffeine out of the system. In severe cases, doctors will use breathing support or various methods to correct abnormal heartbeats.