Too much coffee!


In my grant writing frenzy the last few days, this could easily have been me:

Jasmine Willis, 17, developed a fever and began hyperventilating after drinking seven double espressos while working at her family’s sandwich shop.

The student, of Stanley, County Durham, was taken to the University Hospital of North Durham, where doctors confirmed she had overdosed on caffeine.

She has since made a full recovery and is now warning others about the dangers of excessive coffee drinking.

Ms Willis, who had thought the coffees were single measures, said the effects were so severe that she began laughing and crying for no reason while serving customers at the shop.

She developed a fever and began struggling to breathe after being sent home by her father.

Good thing I don’t drink expresso. I just drink regular coffee, which means I’d have had to drink an awful lot to reach such levels. Frequent trips to the bathroom to empty my bladder would probably have kept me from reaching such toxic caffeine levels. That makes it harder for me to turn into Too Much Coffee Man. On the other hand, yesterday it was like someone turned on a switch and the pollen assaulted my sinuses, inflaming my hayfever, causing my eyes to gush torrents and in general making me miserable; so, unable to stand it any more, I finally broke down and took some Sudafed. Nothing like Sudafed and coffee, is there? Of course, I wouldn’t have done it if I were operating today; Sudafed and coffee aren’t exactly great for the steadiness of hand needed to operate. Coffee alone, as long as it’s not that much, but combining the two is bad.

In any case, the grant’s done. I was up quite late last night putting the final touches on it; all that’s left is one last run-through and then the upload and submission, which I will take care of this morning. My mind is fried, and at times like this I’m so tired of it that I don’t even want to think about my own research anymore, even though normally I consider it fascinating enough to devote my career to it wholeheartedly. Last night, though, after I finished this monstrosity (on all-too-short notice, I might add), even though it was nearly 3 AM and I was utterly exhausted and sleep deprived, I was still too wired and wide awake to go to bed right away, yet too whacked out from my mental effort to write any serious medical or scientific posts for today. Don’t worry, though. I have a couple of short (one might even say “non-Orac-ian”) odds and ends that will appear later today that I’ve been meaning to post and never quite managed to. I also took the time to slap down an annoying troll, which always makes me feel better after the torture of a grant application.

Just hope against hope that the submission website doesn’t go down when I’m finally ready to upload in a couple of hours.


  1. #1 blf
    August 15, 2007

    Good thing I don’t drink expresso. I just drink regular coffee, which means I’d have had to drink an awful lot to reach such levels.

    Er, possibly not. I’ve always understood espresso has less caffeine per serving than a cup of drip or filter coffee. The Wikipedia article concurs (and yes, I do realise referencing an encyclopedia is dubious), and indicates this remains true even for a double espresso (emphasis added):

    The world’s primary source of caffeine is the coffee bean (the seed of the coffee plant), from which coffee is brewed. Caffeine content in coffee varies widely depending on the type of coffee bean and the method of preparation used;[12] even beans within a given bush can show variations in concentration. In general, one serving of coffee ranges from 40 milligrams, for a single shot (30 milliliters) of arabica-variety espresso, to about 100 milligrams for a cup (120 milliliters) of drip coffee. Generally, dark-roast coffee has less caffeine than lighter roasts because the roasting process reduces the bean’s caffeine content.[13][14] Arabica coffee normally contains less caffeine than the robusta variety.

  2. #2 Scott Simmons
    August 15, 2007

    Yes, but the servings of espresso are much smaller … You can throw back a shot pretty quickly & then go back for another. Whereas with full cups of regular coffee, the sheer volume would start causing you problems before you got to the seventh cup, I’d think.

  3. #3 Mike P
    August 15, 2007

    the sheer volume would start causing you problems before you got to the seventh cup, I’d think.


    As an experienced (read: superaddicted) connoisseur of the bean, I can attest that it is extremely difficult to drink that much coffee without taking a bathroom break. However, here’s how one could achieve something similar: red eyes. Well, that’s what they call them where I’m from, but I’ve heard them called other things as well. Basically, a shot (or more) or espresso in a cup of coffee. So let’s say you can drink ~3 cups of coffee in a sitting. Certainly not impossible. And let’s say each of those was a red eye. That’s 3 shots (or more) or espresso plus three cups of coffee… that’s right around the caffeine levels of the 7 espresso shots the girl did.

  4. #4 c-serpent
    August 15, 2007

    Try drinking two or three cups of good strong coffee and eat a 1/4 lb or so of chocolate-covered espresso beans 🙂

  5. #5 Dirkh
    August 15, 2007

    Balzac was so addicted to coffee that he drank 50 cups a day and sometimes supplemented that by EATING his coffee. He was particularly fond of a bowl of cold grounds on an empty stomach.

    He died of hypertrophy of the left ventricle of his heart, believed to have been caused by the excessively high blood pressure produced by his caffeine addiction.

  6. #6 G. Shelley
    August 15, 2007

    Apparently, her excuse is that she didn’t realise they were double espressos. Having had an espresso once, even seven singles seems excessive to me.

  7. #7 Pieter B
    August 15, 2007

    I can’t vouch for the accuracy of this, but from a Caffeine FAQ

    Is it true that espresso has less caffeine than regular coffee?

    Yes and no. An espresso cup has about as much caffeine as a cup of strong coffee. But servings for espresso are much smaller. Which means that the content of caffeine per milliliter are much higher than with a regular brew. Moreover, caffeine is more quickly assimilated when taken in concentrated dosages, such as an espresso cup.

    Several other sources tend to confirm that a single shot of espresso has about as much caffeine as a standard cup of regular brew.

  8. #8 blf
    August 15, 2007

    Ah, the concentration of the caffeine (i.e., mg per ml): That could be it. The quantity of caffeine is (apparently) considerably less in a shot of espresso, as is the amount of liquid, but the ratio is higher. Using the Wikipedia figures, that’d be 40mg/30ml (espresso) to 120mg/100ml (drip), or c.1.33 (espresso) to c.1.20 (drip); i.e., espresso has c.110% the caffeine of drip coffee. And that’s per single shot–with double shots, it’d be over 200%. Orac’s “Yikes!” now seems a bit more plausible (especially, I presume, if the lady in question is particular sensitive to caffeine?).

  9. #9 blf
    August 15, 2007

    Oops! Strike that bit about 200%–double shots double the liquid as well as the caffeine, so it’d stay c.110%.

    Guess I had too much coffee today? Or maybe not enought beer (he says noticing it’s time for the pub)? 😉

  10. #10 AJ Milne
    August 15, 2007

    Yep. Scary.

    I do occasionally get to six espressos… over the whole course of the day. Rare thing, generally. And generally, if I get those last few into me, it’s gonna be headed into the evening, the espresso imbibed in a latte that’s likely to take a little while to go down, ’cause I got work to do through the evening… And even that can create a certain heightened level of anxiety, especially if it chases an earlier one a little too closely. Really not a very pleasant thing, overall.

    But fourteen? Fourteen?! Geez.

    Note to self: never do that. Second note to self: cut back a little, too.

  11. #11 Melissa G
    August 15, 2007

    Sudafed and coffee? Hmmm… (makes mental note for next deadline)

  12. #12 skyotter
    August 15, 2007

    i’ve gotten it from two sources that a lethal dose of caffeine is +/- 100 cups of coffee (i presume they meant 8-oz cups)

    and one of those sources was Futurama which, as we all know, always did impeccable research

    (the other was Coffee: a dark history by Anthony Wild)

  13. #13 Dr Aust
    August 16, 2007

    Re. the teenager making herself ill with coffee, the old adage that “the dose maketh the poison” comes to mind here.

    Some info on the caffeine content of various different caffeinated drinks, including coffee brewed different ways, is here:

    From these numbers one would estimate Jasmine (the girl in the news story) had probably taken about a gramme (1 g) of caffeine over the course of her shift. This is not a huge dose by any means, although if she was on the small side that wouldn’t help. However, I think it is a significant possibility that some of the reported effects in her case include an element of “panic response” once she began to feel a bit funny. Adult fatalities from dosing yourself with caffeine would usually mean taking at least 10 g (around ten times as much as she probably took) – last time I looked the lowest reported “fatal caffeine overdose” dose in an adult was on 6-7 grammes.

    Caffeine intoxication (as the docs would say) is not THAT
    uncommon, but it is almost never due to coffee drinking. It typically arises when some idiot has taken a whole tube of NoDoze or similar caffeine tablets. Far easier to take enough caffeine to make you ill as pills (e.g. ten 200 mg tablets, sold over the net by numerous idiot online vitamin stores, would gets you a pretty whopping 2 g of caffeine) than from ODing on Mocha Java. The caffeine bad effects might also be enhanced if you were taking other stuff at the same time (booze, other stimulants, some prescription drugs etc etc).

    Among regular “several a day” coffee users, surveys say daily intake is supposed to average about 300 mg, although if you drink several cups a day of filter coffee and/or Starbucks grande Americanos (or equivalent) I would think you could easily exceed 1 g a day (see bif’s posts above). Of course, habitual coffee drinkers almost certainly develop tolerance to the physiological and psychological effects of caffeine.

    One scientific problem in ALL the many “coffee is good / bad for you” stories is whether the effects are due strictly to caffeine (and other methylxanthines) or to other components in the coffee (e.g. things with antioxidant actions). Extracting beans with hot water gives a complex mixture, to say the least. And there is also the interesting idea that how you make the coffee almost certainly changes the exact broth of coffee chemicals that you get out.

  14. #14 Dr Aust
    August 16, 2007

    PS Apologies, cross post there, ignore if you’ve seen similar on Grrlscientist’s Caffeine column

  15. #15 Rebecca
    August 16, 2007

    “Sudafed and coffee? Hmmm… (makes mental note for next deadline)”

    Ew… no. Don’t do it, Melissa. I’ve scared myself several times with that combination. It’s a truly unpleasant jittery sort of feeling with heart palpitations. Not good.

  16. #16 Melissa G
    August 16, 2007

    Heh– no worries there, Rebecca!

    The silliest attempt to abuse of caffeine I ever perpetrated was in college, when I was attempting to pull an all-nighter studying for an astronomy test. I took two Vivarin and washed it down with a quart of Mountain Dew mixed with coffee (disgusting!!!). I was asleep an hour later.

  17. #17 Dirkh
    August 16, 2007

    Metabolisms vary. During allergy season, I frequently combine sudafed and coffee without any noticeable ill effects.

  18. #18 Drugmonkey
    August 17, 2007

    Dr. Aust, there is at least a little backing for a real effect here. Namely malignant hyperthermia. From a review by Rosenberg et al( Orphanet J Rare Dis. 2007 Apr 24;2:21.)
    “The classic signs of MH include hyperthermia to marked degree, tachycardia, tachypnea, increased carbon dioxide production, increased oxygen consumption, acidosis, muscle rigidity, and rhabdomyolysis,”.

    ok. and what about caffeine you ask?

    “Diagnostic testing relies on assessing the in vitro contracture response of biopsied muscle to halothane, caffeine, and other drugs”

    Halothane because this is a (the?) big clinical problem, i.e., malignant hyperthermic reaction in surgery from what I can tell. But caffeine seems to be a go-to for in vitro studies of muscle contracture in the related literature.

  19. #19 Dr Aust
    August 18, 2007


    Interesting idea, but quite apart from malignant hyperthermia (MH) being seriously rare (1 in 5000 people? 10,000?), the amounts / doses of caffeine involved make it a stretch. The dose of caffeine involved is almost certainly too low for a “direct” muscle response, even for MH muscle – I speak as someone who spent several years sticking caffeine on bits of muscle in lab experiments.

    Either by calculating dose (mg or g of caffeine) divided by volume of distribution in the body (crude back of envelope calculation), or by looking through the pharmacokinetic literature for caffeine (fancy version), one can guesstimate that if you take 0.3 g of caffeine all at once (a regime often used in experimental studies), and assume negligible metabolism / excretion, the caffeine concentration in extracellular fluid (ECF, the fluid bathing the cells) will reach a peak value of about 15-30 micromolar (uM) after about 30-60 min. Even with a dose of caffeine of about 1.5 g (which would be a hell of a lot in terms of coffee drinking), and in a small person (less volume to distribute into), the [caffeine] is hardly going to reach 200-300 uM. To cause contracture via a direct effect on even MH skeletal muscle caffeine would have to be 1 milliMolar (1 mM) plus.

    Of course I guess skeletal muscle “hyperactivity” could occur at sub-mM concentrations, but given that she drank the stuff over the course of several hrs, and that she probably took nearer 1 g than 2 g, I would guess the caffeine in her ECF at low tenths of millimolar. So direct skeletal muscle effects would be unlikely, IMO.

    [Since she has been telling other kids about her experiences it may be that she will get written up by her doctors as a case report, in which case we may learn the exact lab values. I would love to know what her blood caffeine conc really was when she arrived at the ER. Make a good physiology / pharmacology teaching scenario.]

    Of course, 150 uM caffeine in your body for an extended period is not harmless – caffeine does most of the bad stuff by “sympathomimetic” effects (i.e. by mimicking activation of the sympathetic nervous system or SNS), so “fight or flight”, raised heart rate, faster breathing etc etc. If people do take enough caffeine to poison themselves then they can get serious cardiac arrhythmias.

    The likely effects of drinking too much coffee – but not enough too make you life-threateningly ill – would be feeling dizzy and light-headed, agitated, a bit sick, heart palpitations (occasional extra beats, sort of feeling a “thump” in your chest – which is not the same as a dangerous arrhythmia, but is definitely disconcerting when you are aware of it). All of which would be quite likely be make someone panic seriously if they thought they’d poisoned themself. At which point sympathetic nervous system overdrive from panicking would cause tachycardia (accelerated heartbeat), fast breathing that would make you feel weirder still as your blood gases would get out of whack, etc etc.

    None of which is to say that the girl wasn’t getting nasty scary effects from sinking way more caffeine than was sensible for her – just that it is over-simplistic to say that caffeine per se caused ALL the effects described in the news stories. Panic is a powerful thing, and since caffeine and panic are both working through the SNS it would be hard to tell which was which.

    I would suggest that to a journalist it makes a better news story as “teenager nearly dies of caffeine OD” than as “teenager treated in hospital following funny turn which may have been combination of too much coffee and panic reaction”

    The only thing that is a bit odd to me is the reported fever. But although fever is reported in caffeine poisoning, it could also just mean she had an infection of some kind at the time, which would also make you more likely to feel lousy if you overloaded on caffeine.

    A final thought is that the stories said she was “allowed home after a few hours of observation”, which suggests to me “bit too much coffee plus panic” rather than “enough caffeine to nearly die” – the latter of which I would predict would have got you at least admitted to hospital overnight.

    If you don’t buy my line about “the power of panic”, here’s a real example. Six or seven years back we had a med student start to hyperventilate, feel nauseous and nearly faint after being given a common prescription drug as part of a teaching lab class. Cue big panic in the lab, “what if she’s having an adverse drug reaction?”, student thought she was going to pass out, was attended by resident medic, was taken across to the ER, etc. etc. An extensive enquiry later, involving sundry MedSchool high-ups, concluded that it was almost certainly not a drug reaction but a panic attack. (Also turned out the student in question hadn’t eaten for 24 hrs beforehand…!)

  20. #20 Julia
    August 26, 2007

    I love Too Much Coffee Man! 😀

    My brother-in-law likes a lot of caffeine. The first time I met him, he was in college and pulling an all-nighter (something about a physics class), and had a large mug containing double-strength coffee with tea bags added for extra measure. That made quite an impression on me. (And he wasn’t actually dating my sister until more than 10 years after I met him that time, and when she told me who she was dating, I asked, “Was he that guy with the mug of Caffeine that night?”) But to the best of my knowledge, he’s never pulled that bad of a stunt, inadvertent or not.

    (At least he’s easy to shop for — if I run across anything new with a caffeine molecule diagram, that’s going into the gift bin for him.)

New comments have been temporarily disabled. Please check back soon.