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.



Heart attack can ensue along with a coma. The amount required to do so is far more than most could comfortably get to. The most common deaths seem to be from long term exposure. I am no doctor but according to a medical textbook I was shown, that is possible.

On a separate note, I am a caffeine addict and just upped the ante. I started taking 300mg or 200mg pills depending on the day. I can take the 200mg pills twice a day and I am sure will eventually reach three a day. I love the feeling, sure sometimes I get a little sick but if you drink enough water and have food in your stomach you are fine. I only have one curiosity...

Is caffeine in liquid form more apt to be absorbed and processed by your body than dry pill form which has to be broken up and absorb whatever liquid is available?

Come on...

You guys aren't going to have a stroke or heart attack because of caffeine. You're going to get the jitters and it just won't feel very pleasant. What you guys need to remember is that you CAN'T JUST BELIEVE EVERYTHING YOU READ ON THE NET. Check your sources. Look at medical journals or medical books that are written by reputable Doctors or experts on the subject. Anyone can just write anything on the net. Do what the scholars and people who attend or attended institutes of higher learning do and make sure the people who are writing these articles are worth their salt.
Keep in mind that everyone is different and some people have a much higher tolerance for caffeine and other drugs than you do (or less tolerance). Factor in weight, whether the weight is mostly muscle or fat, age, the amount of caffeine normally taken by the person on average, how long the person has been consuming caffeine, ect. No one here can DEFINITELY tell you how much caffeine you can take without feeling sick. Only a Doctor that can SEE you can make that assessment. :)

Caffeine OD

This is not a topic that should be taken lightheartedly. I just experienced many of the symptoms described in the above article and it was not something to be brushed aside. It happened a day ago at 10:30pm, 30 minutes after my lunch at work. Earlier in the morning I drank a large mug of coffee, ate 2 tacos (at 1pm) and had a monster at 10pm. I have never felt so close to mortality before. I got off the line after feeling a slight disconnect between my head and body. I had felt this feeling occur before but it never escalated from this point, I was also slightly out of breath in days past but drinking lots of water seemed to help. Why I left the line was because of the force with which my heart beat was so strong that I started to panic. I walked up some stairs feeling even more lightheaded and felt like I was going to pass out while my heart was racing. all the while seemingly trying to burst from my chest. Sitting down helped somewhat, but what really seemed to calm me down was that the lady supervisor there gave me some hand sanitizer on a Kleenex and told me to just smell it, that it would help keep me calm. While I was going through this I was still light headed so I kept trying to keep my breath up so as to not pass out, nice deep breaths. It just got scarier from here on as my blood pressure seemingly skyrocketed and I struggled from breath even more. All that helped were a few signs here and there that I read over and over again because for some reason sounds around my just made what I was going through worse. If I talked, I felt like I lost ground in getting better because I'd feel even more light headed. If I heard someone talking to me I'd also feel my heartbeat pick up it's rising pace even more. So I was intent on staying quiet and just keeping my mind as calm as possible with visions of hospital bills and my own mortality running through my head. I was told to ingest something sweet while this was happening. I struggled to lift my arm up to drink some orange juice and every time I'd lift my arm to my lips I got this sudden rush of palpitations but as I kept on slowly sipping that juice down suddenly I started to feel like my heartbeat wasn't speeding up anymore or beating out of my chest so much. I was still out of breath and weak from the trembling of my legs that had gone on since this started. Suddenly I was somewhat peaceful. I was finally able to tell the supervisor I was getting better and the visions of my mortality and hospital bills were somewhat slipping away... I tried moving around some just to test my capabilities. I knew my legs were weak from so much trembling and that I was still a bit light headed so I knew I'd have a tough go at 'getting up off that chair. An hour had passed since I'd been going through this now as I got up I noticed my heartbeat was pretty slow almost "weak like". Like it couldn't keep up with the actions I was doing. Simply standing and taking three steps I felt that sensation creep up on me again. My heartbeat started racing and beating harder than before, like it came back with a vengeance or something. That was the really scary part. I thought I was in the clear and all of a sudden it takes hold of me again. Do you know about those little stress toys people squeeze? It felt like someone was using my heart as one and they were giving it a real good go. All I did was focus and eat the skittles placed besides me, once again trying to keep my breathing level to something that my heart would possibly need. I thought... If my heart is beating like I just ran 3 miles nonstop I'll just breathe accordingly else I may pass out and look like a real pussy at work. So I did that and got through that again. This time I felt like some sort of crash had hit me. I felt weak, really weak. Still a little out of breath but it was manageable now. I got up this time and was able to walk down the stairs from the supervisors office to the work floor. I couldn't walk about half a block though to were the water coolers were at. You see I had been drinking water nonstop throughout this episode in an attempt to flush out the monster I had just ingested. Well I eventually was able to walk there and my ability to walk increased as I was able to comfortably feel like walking further and further distances. I kept close to my water source which was conveniently next to the bathroom. For the next hour and a half I just drank water and pissed it out drank water and pissed it out. Still had some moments of a slight itty bitty climb in heartbeat but that I attributed towards moments of panic and if I sat down for 5 minutes they'd go down. Walking outside to the cool night air also helped to calm me down. From this point on it was a struggle of the mind. My body seemed to be getting better but my mind was full of doubt and panic which I had to keep pushing aside. I left work at 1:30 a.m 3 1/2 hours of that shit and I was going home. Got home, slept for 2 hours. Woke up with a rapidly beating heartbeat. Wasn't hard and fast, just normal and fast, I figured panic attack from the trauma earlier but went to the hospital anyway. When I got to the hospital bed I immediately stopped the small amount of trembling that had been going on in my still. and I knew it was in my head. They did an EKG (checks your heart health) checked my blood sugar, that was fine. Check my pulse and blood pressure, also fine. I was told by the doctor that it was probably a caffeine overdose and to lay off of it for a while. He said I was fine. Still though I have micro panic attacks where I feel like I have to take one deep breath to even me out and then I breathe normally again. I wouldn't make light of anything like this. Everyone should watch their caffeine intake carefully. People have died from this. Small amount of people but if it's worse than what I felt, and it probably is. I wouldn't wish a death like that on anybody. Hope everyone here is well.

I totally agree with

I totally agree with you...not everyone is the same and you cant believe everything your read. I went through a very rough time with certian drugs and I looked up the withdrawl symtoms and read peoples stories and I totally freaked myself out. Yeah what I went through was bad but nothing like what I read! Everything depends on your body and what you can tollerate and how much you take for how long.

Actually yes you can have a

Actually yes you can have a heart attack from too much caffine. Caffine makes your heat beat really fast, which is your heart pumping blood harder and faster. When there is too much going on and your heart can't take it thus a heart attack. There have been a couple of reported cases that people have died because they had a heart attack due to an overdose of caffine. It just depends on your tolerance and believe me their will reach a point when your body says enough is enough.

you can DIE from drinking too much water too.

you are WRONG. you CAN die from a caffeine overdose. there was a report in the UK where a girl workin gin a cafe nearly died from drinkin more than 20 cups of espress in 1 DAY. she had to be brought to the hospital and given something to reduce the effects of poisoning.
like everything else, coffee should be drank in moderation.
on that note -
you can DIE from drinking too much water too.

You are very wrong on this.

You are very wrong on this. If you are familiar with caffeine supplements taken for exercise and endurance as well as body building...... they very much can make you extremely sick as well as cause irregular heart beat and long term affects.

Caffeine overdose

I was in amsterdam a few days ago and took some legal highs that had about 400mg of caffeine in. I didnt know this at the time and when i started crashing i had a servere headache for a few hours, no balance, irregular heartbeat and haluciniations. They are deffinatly something i will not be taking agian. I still get slight headaches every now and then (although my wisdom teeth are coming through atm), especially if i do an activity which raises my blood pressure. Have i got anything to worry about?


earlier today i took 24 pro plus for a dare, Stupid i know but i dont care - i'll do most dares, anyway - nothing happened we measured my pulse rate/heart beats per min before, and every 30mins after taking them up till now and nothing happened, its basicly still the same, i dont feel any less tired or had any bursts of energy - do these only work on certain people? its the same when i take any "Stimulant" though, i just don't seem to be stimulated

You can take your coffee, but

You can take your coffee, but you`ll feel the changes soon. You have to take care of you as soon as possible, as much as possible. I have took a long time many doses. After a short period, i had heart beatings and i was tremble like an aspean leaf! So , my advice is to stop now! Good luck!

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