What happens if you overdose?

From Desk Reference to the Diagnostic Criteria from DSM-3-R (American Psychiatric Association, 1987):

Caffeine-Induced Organic Mental Disorder 305.90 Caffeine Intoxication

  1. Recent consumption of caffeine, usually in excess of 250 mg.
  2. At least five of the following signs:
    1. restlessness
    2. nervousness
    3. excitement
    4. insomnia
    5. flushed face
    6. diuresis
    7. gastrointestinal disturbance
    8. muscle twitching
    9. rambling flow of thought and speech
    10. tachycardia or cardiac arrhythmia
    11. periods of inexhaustibility
    12. psychomotor agitation
  3. Not due to any physical or other mental disorder, such as an Anxiety Disorder.

Basically, overdosing on caffeine will probably be very very unpleasant but not kill or deliver permanent damage. However, People do die from it.

Toxic dose

The LD_50 of caffeine (that is the lethal dosage reported to kill 50% of the population) is estimated at 10 grams for oral administration. As it is usually the case, lethal dosage varies from individual to individual according to weight. Ingestion of 150mg/kg of caffeine seems to be the LD_50 for all people. That is, people weighting 50 kilos have an LD_50 of approx. 7.5 grams, people weighting 80 kilos have an LD_50 of about 12 grams.

In cups of coffee the LD_50 varies from 50 to 200 cups of coffee or about 50 vivarins (200mg each).

One exceptional case documents survival after ingesting 24 grams. The minimum lethal dose ever reported was 3.2 grams intravenously, this does not represent the oral MLD (minimum lethal dose).

In small children ingestion of 35 mg/kg can lead to moderate toxicity. The amount of caffeine in an average cup of coffee is 50 - 200 mg. Infants metabolize caffeine very slowly.


  • Acute caffeine poisoning gives early symptoms of anorexia, tremor, and restlessness. Followed by nausea, vomiting, tachycardia, and confusion. Serious intoxication may cause delirium, seizures, supraventricular and ventricular tachyarrhythmias, hypokalemia, and hyperglycemia.
  • Chronic high-dose caffeine intake can lead to nervousness, irritability, anxiety, tremulousness, muscle twitching, insomnia, palpitations and hyperreflexia. For blood testing, cross-reaction with theophylline assays will detect toxic amounts. (Method IA) Blood concentration of 1-10 mg/L is normal in coffee drinkers, while 80 mg/L has been associated with death.
  • Emergency Measures
    • Maintain the airway and assist ventilation. (See Appendix A)
    • Treat seizures & hypotension if they occur.
    • Hypokalemia usually goes away by itself.
    • Monitor Vital Signs.
  • Specific drugs & antidotes. Beta blockers effectively reverse cardiotoxic effects mediated by excessive beta-adrenergic stimulation. Treat hypotension or tachyarrhythmias with intravenous propanolol, .01 - .02 mg/kg. , or esmolol, .05 mg/kg , carefully titrated with low doses. Esmolol is preferred because of its short half life and low cardioselectivity.
  • Decontamination
    • Induce vomiting or perform gastric lavage.
    • Administer activated charcoal and cathartic.
    • Gut emptying is probably not needed if 1 2 are performed promptly.
Appendix A
Performing airway assistance.
  1. If no neck injury is suspected, place in the "Sniffing" position by tilting the head back and extending the front of the neck.
  2. Apply the "Jaw Thrust" to move the tongue out of the way without flexing the neck: Place thumb fingers from both hands under the back of the jaw and thrust the jaw forward so that the chin sticks out. This should also hurt the patient, allowing you to judge depth of coma. :)
  3. Tilt the head to the side to allow vomit and snot to drain out.

From conversations on alt.drugs.caffeine:

The toxic dose is going to vary from person to person, depending primarily on built-up tolerance. A couple people report swallowing 10 to 13 vivarin and ending up in the hospital with their stomaches pumped, while a few say they've taken that many and barely stayed awake.

A symptom lacking in the clinical manual but reported by at least two people on the net is a loss of motor ability: inability to move, speak, or even blink. The experience is consistently described as very unpleasant and not fun at all, even by those very familiar with caffeine nausea and headaches.


i know nothing happens

i know nothing happens right?! i feel ripped off everytime i try

you are very stupid

you are very stupid

Coffee Diet?

Hi all. Two months ago I began the coffee diet recommended by a close friend. It says I can drink as much coffee as I want, but can't eat anything. I usually drink 15 - 20 cups of coffee a day, and I feel well and sleep ok.

My concern is the long-term effects. Are there any dangers of drinking coffee long term?

Coffee diet

Yes there is considerable danger of drinking this much coffee long term. You didn't mention your age but I suspect that you are fairly young. As you may or may not know...as we get older we develop higher blood pressure. Drinking too much coffee raises our blood pressure as well. Adding the two together you can possibly develop what I just have. My normal blood pressure is about 140/70 but when I drank just one Starbucks grande today it shot it up to 177/80. Two in a day shot it up to 195. This is obviously not healthy as people die from hypertension.

You are not dieting. You are

You are not dieting. You are starving yourself and using coffee to suppress your appetite.

Seek professional help. You may have a serious food-related neurosis.

are u stupid??? what do u

are u stupid??? what do u think..what kind of question is that? of course thats not safe!!

RE: Coffee Diet?

Talk to a doctor. I assure you this is far from a healthy diet and the amount of coffee is only a small piece of the problem. The lack of food is even worse. Talk to a doctor and see what you need to do to get your system back into balance.


When i was 12 i took some pro plus caffeine pill unaware at the time of the horrible negative affects that they can cause. I had taken six of the tablets which is 300mg of caffeine in less than 10 seconds felt fine and i thought this was a great idea then it was about 45 minuets after i took them i was in class and my heart started beating faster and faster and i couldn't concentrate at anything and when people started moving round the classroom my head started spinning by this time i had to concentrate on my breathing because sometimes it would be normal and other times i would be gasping for breath.

This carried on for about five hours but this wasn't really the end of it i kept on feeling that i was going to be sick and i didn't really feel like eating. later that night i felt like nothing happened and couldn't really remember the day i just had this was about 1:30 am and because of the excessive amount of caffeine i couldn't really get to sleep. By morning i felt like normal.

Please comment and tell me about your experiences and what effects you have had


I had a similar experience. I was driving back from the beach, which is about four hours from where I live, and I was so tiered that I drank a Monster energy drink. It didn't take long for me to feel the negative effects. My heart was beating fast and hard. I could literally hear it. I felt so nervous, I couldn't concentrate on the road. I felt extremely nervous about everything; the weather, the other cars, distance, you name it I was nervous. I had to pull over and call the the poison control center and they told me that I was having a caffeine high and that the only way to reduce it was to eat bread. So I did, but unfortunately for me it didn't work. Later on that day, once I got home, I felt tiered and confused just like you. I couldn't remember anything..

When i was 12 (I'm 13 now),

When i was 12 (I'm 13 now), my dad bought some of those sugar light packets, thinking they were the regular kind. Instead, he bought the packs with caffeine in them. As being a kid who likes sugar, i put two packets in one water bottle; not knowing there was caffiene in it. Uh oh... 20 minutes later, I had drinken the water bottle (i'm a heavy water drinker), and i started feeling confused, like i couldn't think straight. I couldn't see straight either, i kept zoning in and out. I was getting hot and sweaty too, (VERY unusual for me, usually i'm freezing all the time) Finally, i looked to see if the crystal light packets contained anything... *Contains caffeine. Once i found out i was on a caffeine overdose, I started thinking of all the possibilities of what could happen to me. I was mostly worried about death... I told my brother what happened (my parents, of course, were some where else). He said just to take everything slow and lay down or watch a movie. While i was watching hte movie, i started feeling like i couldnt sit down, i had to run or something. So i ran around the house for about 10 minutes. then went back to the movie.
the dizziness and lightheaded came and went. The sweatiness went on for about 3 hours. The confusion stayed for about 2 hours.
Since then i have limited my pop intake and so forth.

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