Laugh? I nearly died.

March 10th, 2007 by Ben Goldacre in bad science, drurrrgs, scare stories | 62 Comments »

Ben Goldacre
Saturday March 10, 2007
The Guardian

Obviously nobody is more worried than I about the hippie crack epidemic: nitrous oxide – better known as laughing gas – has hit the news, after the death of a man with a plastic bag over his head, and a cannister of the drug connected to himself.

Now, I will never speak ill of the dead, and I feel very sorry for this poor man, but equally we must all take responsibility for our actions. Plastic carrier bags are a vital feature of the tramp-chic look I’ve been going with this season – or should I say decade – and to be fair, the one I’m currently carrying my laptop around in reads “plastic bags can be dangerous: to avoid suffocation keep this bag away from babies and children.”

Is there anything else to worry about with hippie crack? Because all drugs carry attendant risks, and it is only by clarifying those risks that we can decide how to manage them. Luckily the Medicines and Healthcare Regulatory Authority has put out a press release, which has manifested itself in various headline stories, mostly under headlines suggesting that nitrous is “no laughing matter”.

The MHRA say this: “Whilst the inhalation of nitrous oxide may be perceived by some as ‘harmless activity’ – there are a number of health risks associated with its inhalation. The ‘rush’ users experience is caused by starving the brain of oxygen. This can cause the user to collapse and injure themselves when falling.”

Now, to be effective, and persuade people to change their behaviour, in public health policy, it is generally considered that your message must be credible, and perceived by the recipient as applicable to their circumstances. This is relevant in campaigns on HIV or smoking for example. I suspect most hippie crack users will already have experimented with holding their breath, and will rightly conclude that their transcendant experience on nitrous is a drug effect; and that it’s an anaesthetic used in hospitals, and in childbirth, so the effect is probably not caused by starving the brain of oxygen; and that the MHRA, of all reputable bodies, is talking nonsense.

In fact, the pharmacology of nitrous oxide is fascinating, and a window onto how we deduce what drugs do in the brain. It seems to work on the NMDA neurotransmitter system, and on the opioid system. Animal models suggested that it might increase the release of opiate molecules made by your own body. To test whether opiates were responsible for the effects on humans, researchers gave nitrous, to people in pain, and then gave an opiate receptor blocker, to see if the analgesic effect was reversed, or changed: the analgesic effect was, but the subjective sensations of being “high” on nitrous were not, even at high doses, suggesting that this aspect of its effect must be mediated by a different neurotransmitter system. It seems likely that these effects are mediated by the NMDA system, perhaps similarly to ketamine. If all those politicians really were “experimenting with drugs” in their youth we’d know a lot more than we do.

But that’s a colossal diversion. Are there any real dangers with nitrous oxide? Well it’s fairly safe overall, and I suppose you could risk manage the “falling over” thing by “sitting down”, but it has been studied very closely for a long time – on account of its widespread medical use, and the worry about chronic low dose exposure for dentists and people who work in operating theatres – and it turns out that it does have a major side effect: it selectively oxidises the vitamin B12 in your body, and affects the folate levels too. Vitamin B12 is needed for a process called methylation, involved in making DNA amongst other things, and without it you have a tough time making new cells. I confess I find the nerdy details of why you get ill from things endlessly fascinating.

There are cases in the literature of people over-exposed to nitrous becoming dangerously B12 deficient, or as the MHRA describe it: “There are also long-term dangers to health (including bone marrow suppression, blood cell problems and poisoning of the central nervous system).” But having said that, in the literature it seems fairly clear that these very worrying effects are reversed simply by giving high dose vitamin B12 (which we also recommend for mothers with growing babies inside them).

This may be rather trendy and “harm reduction” of me, but if I was going to put out a press release on hippie crack, I would advise against using it, but I wouldn’t shoot down my credibility with primary school assertions about its mode of action on the brain, I would state the risks clearly, and if I thought the risks from, perhaps, B vitamin deficiency really were significant and worrying, then I might also mention the harm reduction strategies available, and start monitoring outcomes.

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[Oh, somewhere in the mangle the paper’s version ended up half implying that B12 and folate might be the same thing, they’re not, although both may be affected by nitrous; longer and correct version of copy above etc.]

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62 Responses

  1. BrickWall said,

    March 12, 2007 at 11:13 am

    Jeez my typing is all up the spout of course I meant to say, “assuming they HAVEN’T done it long enough for it to work properly” – Idiot!

  2. Dudley said,

    March 12, 2007 at 12:13 pm

    I was just wondering where you got “this picture” from…

  3. BrickWall said,

    March 12, 2007 at 1:41 pm

    Oh its not my picture, I just found it, its one of my mates’ brothers pictures actually, just kept it for a laugh etc.

  4. stever said,

    March 12, 2007 at 1:43 pm

    re Cdavies 40#

    its very much not recommended to use nitrous made for car engine systems. It apparently has additives in it that could be nasty. recreational use should be with product passed for human consumption, medical or catering.

  5. CaptainKirkham said,

    March 12, 2007 at 5:39 pm

    All I know about this is that there are few things sillier than watching people at a party breathe in and out of balloons. Honestly, it is one of those “reality check” moments. Also, it makes people’s lips go blue. Luvverly.

    But I have to say that this whole MHRA thing sounds like a typical (and typically pathetic) example of the “drugs are baaaaaad” instinct and will not be listened to one jot. It will not be trusted or taken seriously. One person dies because of a plastic bag over his head – honestly, that is not the least bit relevant to people sucking out of balloons using soda syphons.

  6. Robert Carnegie said,

    March 13, 2007 at 1:51 am

    Auto-erotic asphyxiation – , possibly Michael Hutchence – I haven’t got straight whether Paula Yates thought he had or hadn’t. The question was suicide but I think it would have to count either way really?

    It appeared in an episode of [Six Feet Under] recently repeated – a stranger dies at the start of each show and ends up in the funeral parlour. In this case I think characters in the show argued whether it was an urban legend, and I believe they included the “bite on a piece of citrus fruit” part. Other tellers of the story seem to have been unsure of where to put that, so to speak. (not really work safe, like that matters by now either) claims “between 500 and 1000 deaths occur annually in the United States from this”, which is citeless and vague.

  7. fridgemonkey said,

    March 13, 2007 at 1:55 pm

    Does anyone know if there’s an increased level of risk associated with taking N2O and helium at the same time? Because there’s an unexploited market out there for squeaky-voiced hilarity, surely.

    Unfortunately inhaling Nitrous from a balloon, which has just been dispensed under pressure from a cylinder or a whipped cream dispenser, chills the vocal chords [cos the gas is cold]. So the hight voice helium effect is cancelled out by the lowered voice from the cold N20.


  8. Suzy said,

    March 13, 2007 at 10:46 pm

    Glad to see the Folate / B12 thing was sorted

  9. raygirvan said,

    March 15, 2007 at 1:03 am

    500 and 1000 deaths …citeless and vague

    True, but it’s not far different from the figure cited in an Andrew P Jenkins medical paper that’s easy enough to Google. Jenkins and others argue that it’s under-reported for various reasons, particularly in the case of teenage deaths where parents clean up the scene. The profile of potential cases commonly turns up in the papers: teenage male hanging that isn’t clear suicide (e.g. no note, no history of self-harm, no stressful circumstances) and the police find no evidence of foul play – investigation fizzles out into a coroner’s open verdict.

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