Is alcohol effective as a painkiller?

How many people have sustained an injury (accidental or other) after a few too many drinks, to find that the pain only really kicks in after they have sobered up? Pain experienced the morning after our drunken exploits may lend weight to the established belief that alcohol provides an effective form of pain relief. Historically, alcohol was a predecessor to modern anaesthetics. It wasn’t quite as long ago as we might imagine that patients were carried into operating theatres in a drunken stupor to undergo surgery. Melzack and Wall recount grisly historical tales of strong men immobilising terrified patients while surgeons amputated a leg or drilled a hole in the skull, often with incredible speed.

Given that the analgesic effects of alcohol appear to be well supported anecdotally, we thought it would be interesting to review the research evidence. We looked at the results of controlled experimental studies assessing the effect of measured dosages of alcohol on experimentally-induced pain. The aim was to establish whether alcohol does result in pain relief and, if so, to quantify the magnitude of this effect.

Given the general level of interest in this area, there were fewer studies than we expected. A systematic search found 18 eligible experimental studies, involving a combined total of 404 healthy participants. All those taking part were exposed to painful experimental stimulation after being allocated to an alcohol or a no-alcohol control condition. Participants were 26 years old on average and were mostly male. Pain was assessed in a variety of ways, including pain ratings (0-10) and pain threshold (the point at which pain is first experienced). Studies were generally of good methodological quality; many reported randomisation of participants to conditions, precise measurements of blood alcohol and use of placebo groups who were given negligible levels of alcohol to reproduce its taste and smell.

A meta-analysis of the data from these studies provided robust support for the painkilling effects of alcohol. A mean blood alcohol content (BAC) of approximately 0.08% (around two pints of lager/medium glasses of wine) produced a small elevation of pain threshold and a moderate-to-large reduction in pain ratings. For pain ratings, pain was rated at around 5/10 in the control condition, which was reduced by around 25% after administration of alcohol. A dose-response relationship was also observed, with increasing levels of alcohol resulting in increasing analgesia (with alcohol dosages ranging from the equivalent of around half a pint of lager to three pints). Full results are published in the Journal of Pain.

Overall, these results suggest that alcohol does deliver effective relief from pain – at least for the type of relatively short-term pain induced in the laboratory. While there is uncertainty regarding the precise mechanism(s) underpinning the pain relieving effects of alcohol, suggested mechanisms include both indirect (e.g. through the reduction of anxiety) and direct effects (e.g. via the blocking of NMDA receptors in the central nervous system).

It is difficult to know how well these results generalize to acute pain outside of the laboratory. It is nevertheless interesting to note that pain intensity ratings of 5/10 can represent the threshold at which pain can have a serious impact on normal functioning. It is also hard to know whether the same level of analgesia observed for experimental pain extends to chronic pain complaints (e.g. back pain), as these two types of pain differ in their emotional, cognitive and physical components. Nevertheless, if alcohol blunts pain partly through reducing anxiety and other negative mood states, as has been suggested, it could be speculated that alcohol may be an especially effective analgesic for clinical pain states where levels of emotional distress are often high.

One implication of these findings is that the painkilling properties of alcohol could contribute to the increased usage of alcohol observed in patients with persistent pain. Furthermore, the accessibility and relative inexpensiveness of alcohol is likely to encourage its use as an analgesic in preference to more difficult-to-obtain drugs or interventions. Of course, excessive alcohol consumption can present substantial threats to long-term health and provides an increased risk for developing future chronic pain conditions. Furthermore, these findings suggest that the level of alcohol consumption needed to provide sustained moderate-to-large analgesia for persistent pain exceeds most countries’ guidelines for safe drinking. As such, efforts to promote awareness of alternative pain management strategies (e.g. physical therapy, exercise, controlled use of pain medication) with fewer long-term health consequences to vulnerable people is likely to be beneficial.

About Trevor Thompson

Trevor Thompson University of GreenwichTrevor Thompson is a senior lecturer in the Psychology department at the University of Greenwich, UK. He has previously worked as a consultant statistician in the area of patient-reported outcomes in the US. He enjoys research examining the neurophysiological foundations of pain and exploring the potential for technology in pain management. But hates mime artists.

Reference

Thompson T, Oram C, Correll CU, Tsermentseli S, Stubbs B (2016) Analgesic Effects of Alcohol: A Systematic Review and Meta-Analysis of Controlled Experimental Studies in Healthy Participants. J Pain. 2016 Dec 2. pii: S1526-5900(16)30334-0.

Comments

  1. Gerry Daly says

    Something we perhaps tend to overlook when studying the chronic pain mindset is that the default setting is different to those without chronic pain. The chronic sufferer ‘expects’ pain in most circumstances, whereas as those without don’t. The pain experience is perhaps the most influencing factor in anyone’s existence, and it does force itself upon consciousness in a way which impacts on behaviour across the board. Even acute pain, with a relative healing expectation, can do do this…that is why it is often quite hard to readjust to a mindset which allows for pain to interfere with everyday plans etc. For the chronic patient, that readjustment becomes their default mindset…in a sense they live with a continuous sub-conscious fear of repetitive re-occurrence.

    The problem with alcohol and the inducement to sleep to negate pain sensations, besides the ‘hangover’ effect, is that continual consumption would more than likely lessen the required resistence that chronic pain patients rely on everyday to help them get on with stuff. It can be an everyday struggle to try and get above the debilitating effects of pain, and I think that having a peaceful and un-interrupted environment is a more attractive option. Alcohol also ups the self-pity aspects, and that can be unhelpful as well.

  2. Gerry Daly says

    That’s an interesting and fairly comprehensive study, although my initial instincts about it would be concerned with the particular demographic targeted and the possible bias towards alcohol due to ingrained cultural influences within that demographic. Basically, I think there would be different conclusions if the study were to be conducted in a remote Asian farming community. However, they can only work with what’s conveniently available, and within those limitations, it seems to show that there is a tendency towards alcohol as a perceived possible painkiller.

    Another aspect that flags itself up to me is the manner of the test. If people are asked about alcohol/pain relationships, that’s what they will respond to, without necessarily giving much thought to why they might opt for alcohol as a possible painkiller in the first place. On the other hand, if people were asked why they think alcohol might be considered a pain relieving aid, the answers might be different. Then they would be obliged to explain their reasoning for assuming the pain killing properties of alcohol….which is probably more what your article was directed at. Too often, the researchers frame their questions according to a limited expectation. Perhaps a certain amount of neuro-nudging towards a pre-conceived conclusion involved in all that !

    For me, an uninfluenced response is what’s required….and even the suggestion that those tested might perceive alcohol as a possible painkiller in the first place is a suggestion too far if a consensus of neutral opinion is to be extracted. Perhaps a question such as…’Do you think alcohol has a role to play in increasing pain tolerance, and if so, why ?’ might elicit more illuminating responses…..rather than assuming that some people might already be convinced about any alcohol/pain relationship before the test begins. Funny thing about pain is that people have a tendency to try and not think about it, and so they never get to do the deeper evaluations of their own reasons. Human nature, I suspect.

    Also noted your comments on alcohol’s pain relieving effects in the waking state. That’s something which definitely needs exploring….but I would ask the question…”Is it really the ‘waking state’ if alcohol has already been consumed ? “. Perhaps it’s more a semi-nonconscious state which allows for a reduced conscious perception of pain. Consciousness requires perceptions to function. Semi-consciousness only requires semi-perceptions. Non-consciousness, which doesn’t function by means of perceptions, requires no perceptions…..therefore no pain. I might be stretching it here but I would even suggest that pain simply does not exist outside the conscious ability to perceive it. In other words, the existence of pain perceptions are strictly limited to the conscious ability to create perceptions…and that’s the only environment where pain perceptions can assume a ‘reality’.

    Slightly off topic there….but relevant I think.

  3. Gerry Daly says

    I don’t think there are many who would admit to drinking alcohol simply to suppress con-current pain sensations. It’s probably much more likely that alcohol is consumed in order to aid the sleep process…..in the knowledge that a deeper sleep offers up less pain possibilities, and possibly even that the pain intensity will have altered on next awakening. Alcohol and sleep are closely related….we know how alcohol can induce an almost non-conscious state. And pain doesn’t register in the non-conscious state. So, the attraction of consuming alcohol to recreate a semi-nonconsciousness is obvious for anyone wishing to alter their pain experience temporarily . However, with the availability of modern painkillers, alcohol has probably moved down the list in terms of what people might consider their best methods for suppressing pain. Personally, as someone with a chronic pain condition, I would vouch for a whisky nightcap as a great sleep enabler….seems to be all about relaxing the relentless awareness of discomfort, thus allowing sleep to happen more easily.

    Gerry Daly Reply:

    PS…………

    Just taking the pain / alcohol / sleep relationship a little further in understanding. Most chronic pain sufferers probably see the deep sleep state as the ‘Great Natural Reliever’ , simply because pain does not register in deep sleep. As such, sleep inevitably assumes most desired state mode in the mindset of the chronic pain patient…..subconsciously it becomes the most comfortable default state, even though they may not be consciously aware that they have changed their priorities in terms of how they perceive their overall status. Most people, without chronic conditions, probably see sleep as an inactive waste of time, to some degree……but to chronic pain sufferers, sleep becomes ‘prime time’ by default, because of the pain relief it offers up naturally. Of course, that might put chronic patients at odds with anyone who’s priorities differ…..i.e. anyone who thinks that the awake state is all important. This is an area where dissonance occurs regularly between operators and patients, because of the different appreciations of most desired default states, and most of that dissonance occurs ‘unknowingly’ to both parties. The problem there is usually that the chronic patients are still holding on dearly to more ‘normal’ expectations and priorities, even though their condition is demanding an almost opposite set of more appropriate default priorities and expectations. And that’s all about continuing to try to feel ‘included’ when your body is telling you that things have changed, and you no longer have similar priorities, even to the very people who should understand your condition best. Basically, the patient attempts to deny their deepest instincts in order to feel ‘included’….and often that results in a mistrust of subjective intuitions and a corresponding lessening of self-efficacy.

    Regarding the alcohol issue, I think that consuming alcohol doesn’t necessarily have analgesic properties. Alcohol does have anti-septic qualities, but as a painkiller, it’s probably more of a pathway to the ‘real’ analgesic properties of deep sleep only. Same for any relaxation inducing drug, really. The goal is to access the pain-free state offered up by sleep, ‘The Great Reliever’.

    Trevor T Reply:

    Thanks for taking the time to post that Gerry, it was a very interesting read. I’d be quite curious to know the degree to which alcohol is commonly used to reduce chronic pain – I’m also tempted to think ‘not much’ although I think it was the Riley et al (2009) study that might have reported that around 25% of surveyed people (I think?) with certain types of pain self-medicate with alcohol, but whether that figure can be reliably generalised outside of the particular assessment methodology they used or is circumscribed to specific types of pain it’s hard to say (haven’t looked at the paper for a while). It certainly seems feasible that alcohol may be effective for managing chronic pain due to mediating effects of sleep, although it’s also interesting to note that we also found pain relief effects in the waking state suggesting direct analgesic properties.

    Trevor T Reply:

    Sorry, forgot to post link to Riley and King study which is:

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2734914/

  4. This is an interesting topic. I both experience chronic pain and want to do research in it after completing my doctorate of PT. I don’t don’t take any form of pain medication (rather I make sure I exercise regularly), and most days the amplitude is anything from light-tolerable. On high stress days though, my pain can get amplified, and I will drink 1 or two glasses of wine that evening knowing that it helps calm things down so that I can get to sleep that evening. Outside of that, I rarely consumer alcohol; overall I’d say I have wine 3 times a month.

    Trevor T Reply:

    Thanks for posting Sarah – it was Interesting to read this along with the other post on alcohol helping with the pain by facilitating sleep. I personally I find I get off to sleep easily after alcohol but also wake up early, so it doesn’t really help me a great deal for that purpose

  5. Luke Parkitny says

    Trevor
    You’ve raised some interesting points about the limitations of the literature. We identified the dose issue too and we’re just getting ready to publish the results of an experimental study looking at the effect of safer alcohol does. Hopefully this might help answer some of the questions.

    Trevor T Reply:

    Excellent, I’m very much looking forward to reading this Luke, and will certainly look out for it with great interest – thanks for posting