Can Caffeine Be Lethal?

A lethal dose of caffeine for a healthy, adult male is about 10 grams. That’s about 70, eight-ounce cups of the strongest coffee you’re ever likely to drink. There has never been a reported case of a fatality from drinking too much coffee. The reasons why this is so are twofold.

First, coffee is very quickly metabolized and excreted, and therefore, it’s almost impossible to accumulate a lethal dose in our systems. Secondly, drinking that much coffee is likely to cause extreme vomiting, and this, again, will reduce caffeine accumulations. But all of this is not to say that people have not been killed by caffeine overdose. It’s caused cardiac arrest and respiratory failure.

One of the first such cases reported in recent history was in 1959 when a 35-year-old woman was accidentally administered 3.2 grams of caffeine in a solution intravenously.
The patient began convulsing, stopped breathing and died. Still another hospital patient was given 0.4 grams of caffeine in the same solution and experienced convulsions.
Fortunately for this patient, the error was discovered in time, the caffeine solution was immediately halted, and the patient recovered. And there are other records of caffeine
overdose. A five-year-old girl ate handfuls of Tri-Aqua tablets one Sunday evening, apparently thinking they were candy. Tri-Aqua is a diuretic and contains about 99 mg of
caffeine per tablet. Within an hour, the little girl complained to her mother of “cold chills” and stomach cramps. Her condition steadily worsened and, within four hours, she
was pronounced dead on arrival at a local hospital. Her caffeine intake had exceeded five grams. She had consumed 54 tablets.

A 45-year-old woman was given 50 grams of caffeine instead of 50 grams of glucose during a routine test. A few minutes later she began to vomit. She died about two hours
later. Her caffeine intake had been enough to kill five healthy men.

But, not all of the caffeine deaths have been accidental. Caffeine also provides the mentally disturbed with a method to commit suicide. One case involved a 27-year-old
woman who was found dead in bed with a suicide note. Her death was ascribed to an overdose of caffeine. The vehicle was apparently an over-the-counter drug.