Caffeine acute toxic effects

Acute Toxic Effects of Caffeine Chronic Effects of Caffeine Use Therapeutic Uses of Caffeine Conclusions Summary... 

This section describes acutely toxic chemicals that produce immediate toxic effects. Because these immediate effects are easier to recognize and study, we know much more about the effects of acute toxicants than about chronic toxicity which inherently requires longer time periods and lower doses. Nevertheless, we may not know all of the toxic effects of chemicals. In Section 4.1.1 you learned that the effects that chemicals cause depend on many factors, including dose and time. Salt, that holy substance praised by Hawthorne, is toxic with a LD50 of 3000 mg/kg, and children have died of salt poisoning. But salt is required in small doses for our well-being and we often use it hberally in our foods. Caffeine is toxic and has an oral LD50 in rats of 192 mg/kg., but you would have to drink about 100 cups of coffee to receive a lethal dose in a few hours. As discussed in Section 4.1.1, the dose makes the poison . Some chemicals may have more than one toxic effect, and the mechanisms of these effects vary markedly. 

The acute oral LD50 (dose sufficient to kill one-half of the population of tested subjects) of caffeine is more than 200 mg kg in rats, 230 mg kg in hamsters and guinea pigs, 246mgkg in rabbits, and 127mgkg in mice. The sensitivity of rats to the lethal effects of caffeine increases with age, and higher toxicity is observed in male than in female rats. 

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