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.


One different symptom

Ok, I read all 26 pages of.comments and I did not see one symptom I recieved.. was on a road trip so had only 1 vivarin tablet with a large ice coffee and a 175 MG red bull within span of 3 hours. I felt great it kept me up and I felt excited and wake on the journey up. I was experiencing the heart racing and mind all over the place and the vibration feeling in leg and arm and pacing alot. Wasn't 3 bad cause I googled it and found out its an overdose that the longest I've seen it last on here is for 3 days so I was calm.. My girl was here with me and calming me down and I tried to have sex and I couldn't get hard.. never happened b4 and she tried very hard.. she said it was prolly cause I couldn't focus so after trying for a hour she gave up.. I got up this morning cause I had to check so I started watching porn and I still didn't get hard.. please tell me someone else experiencedo this and it goes away. Reply

Felt Immobile!

This happened to me just yesterday and it brought me back to this forum! I don't drink a lot of caffeine because I am so sensitive to it. I have been trying to get OFF it altogether but decided to have a coke with my lunch. Afterwards I went into the store to buy groceries and I suddenly felt immobile. Intuitively I knew it was related to the coke I had just drank. This has never happened to me before! Even though I could still actually move, it FELT like I couldn't...and could not get myself to speak. I only shook my head and it FELT like I couldn't talk even though I could. I thought I might be having a stroke but no paralysis. I know this sounds confusing but it's the only way I know how to explain it. I came home scared and tried to rest and it finally went away, but my anxiety is thru the roof and I haven't slept all night. I know I need to QUIT, but it's such a struggle! The more I drink caffeine the more extremely sensitive I become to it.

Caffine can be scary

I overdosed on caffine. They rushed me to the er because my heart rate had been sitting at 190 for about an hour even whole I was laying down. They thought I was on cocaine bit no just caffine. The experience was awful though. I was red and sweaty. My vision was spotty. My chest hurt and breathing was difficult. They hooked me up to lots of meds to calm me and o drank a ton of charcoal. The moral is watch your intake. It is a drug. It also makes your brain activity drop, Especially in your frontal lobe. Ive had to cut it out entirely from my life cause it messed up my brain chemistry and my androgenic system pretty bad. Just be super careful. It can be dangerous and somtimes you get long term effects like my anxiety disorder.


Hey just wondering how long it took for things to go back to normal. I went to the hospital about a 2 weeks ago and my heart still feels kinda funny.


Though coffee has a lot of antioxidants and other nutrients, it has some awful consequences if not taken in moderation. Since am a coffee addict, I always try to take half regular and half decaf just to not to have some of those negative effects. But sorry for the unfortunate incidence that happened to you.

I didn't know there was a

I didn't know there was a such thing as caffeine poisoning I just had a lot of caffeine because I wanted to stay awake but then started to feel really blugh then threw up a lot I took some activated charcoal and am just trying to wait it out is there something I can do to help push it out my system faster

Caffeine effects still lasting 3 days later anyone ??

I went to the er Thursday night after feeling dizzy with a racing heart all test came back normal .. The doctor said he was pretty sure it was from the max dose I took of preworkout 5in a half scoops every 2 scoops was 100mg of caffeine . He also said it had other things in there that were pretty bad . It's now Sunday and all though the muscle twitches and wired feeling have gone my heart tends to race (palpitations) sometimes when I get up to do things . I've drank tons of water . Has anyone else had lasting effects like this that took longer to go away ? I did not have this issue prior I'm sure I would have noticed considering I go to the gym my heart beat would me sky rocket .

Coffee Overdose - hell, don't drink coffee anymore

Drank a big cup of coffee with 30 teaspoons of expensive ground coffee. I think there was like 2000 g of caffeine in it. Result? Vomiting for 2 days. Extreme restlessness, nightmarish anxiety, constant pacing lasted 7 days. Anxiety, especially in the morning and mid-day lasted for more than a month. Never again. I overdosed on caffeine because I was trying to treat my Post-SSRI Sexual Dysfunction, coz I read that caffeine increases dopamine. Which did not work at all.

5 hour energy

I have found this post very helpful. I am a 29 year old adult male. I haven't had any caffeine in at least 6 months. This morning I was very tired after staying up to late last night. I had such a
busy day ahead of me at work, so I decided to try a 5 hour energy shot for the very first time. About 30 min after drinking it, I started feeling very dizzy, shaky, and light headed. I freaked out and had a panic attack. Luckily I was near
A doctors office, and I went in. They said it was a caffeine overdose. I drank lots of water and felt a little better a few hours later,
but still not great. I am now drinking a few beers to help calm my nerves. I'll never drink a 5 hour energy again!


Can you die from 2.5 cups of coffee if you are not a grown adult? (Not a child either, like 16) sorry that this is a stupid question...

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