Tegan Taylor: Well, today's a great day because it's a day that I get to play one of my favourite games, which is where I get Norman to say words and then tease him about his weird pronunciation.
Norman Swan: It's you that's got the weird pronunciation, not me.
Tegan Taylor: Me and the entire nation of Australia say words the weird way and you're the only person that says in the right way.
Norman Swan: Yep.
Tegan Taylor: Okay, could you please give me the name of a common over-the-counter nonsteroidal anti-inflammatory drug?
Norman Swan: I-BU-profen.
Tegan Taylor: Ibuprofen. And what's the other over-the-counter painkiller that isn't that that can cause liver damage if you don't take it responsibly?
Norman Swan: Paracetamol?
Tegan Taylor: Come on, you say it differently to that. I've heard you say it…
Norman Swan: Do I? Paracetamol…
Tegan Taylor: You say para-SET-amol.
Norman Swan: No, no…
Tegan Taylor: Yes, you do.
Norman Swan: No, no, no, that's what Australians say.
Tegan Taylor: All right, fine, you're one of us now. The other word that I find fun to say is the name for paracetamol that they have in the United States, which is acetaminophen…acetaminophen.
Norman Swan: Yeah, much more straightforward.
Tegan Taylor: Yeah, I think so too. And what's the one that's derived from willow bark?
Norman Swan: Aspirin.
Tegan Taylor: Oh yeah, that's the same. Okay, cool, on with the show.
Norman Swan: And the show is What's That Rash? where we answer your questions,
Tegan Taylor: I am health reporter Tegan Taylor, and I'm on Jagera and Turrbal land.
Norman Swan: And I'm Norman Swan, physician and journalist, on Gadigal land.
Tegan Taylor: So we are talking today about over-the-counter painkillers. It's one of those ones that we've had quite a few questions about from various people. Deb is asking; which is better, aspirin or ibuprofen? Are they comparable? And we've also got a question from Bridget, which I think we can also answer in this episode.
Bridget: Hi, my name is Bridget and I'm eight years old, and I have a question for you. How does Panadol get from your mouth to wherever it needs to go in your body?
Norman Swan: Great question there from Bridget.
Tegan Taylor: That's a great question. It's actually one that I've wondered about quite a lot. Because I remember there were ads on the TV a few years ago, Norman, that were since pulled because the ACCC found that they were misleading, where you sort of had a body radiating pain, and the body was kind of clutching, say, it's lower back, and then they took the painkiller and you could see it travelling to that very spot in the body and then killing the pain and like, yeah, that's what I want, my back's sore, I want that thing to go straight there. But of course it doesn't. So how does it know where to go?
Norman Swan: Well, that's a great question from Bridget. Paracetamol (acetaminophen) does not work by going to the part of your body that's sore. Your body gets bathed in this paracetamol when you take it and you absorb it from your stomach or your small bowel. But it actually goes to your brain. And paracetamol works on pain relief (and it doesn't work on all pain relief, by the way) by affecting how your brain works.
Tegan Taylor: I am interested in knowing a bit more about that because my understanding is that we have a pretty good idea of how non-steroidal anti-inflammatories work (and we will talk about them in a sec) but my understanding is that we actually don't really have a great handle on how paracetamol actually works. It works but we don't know how.
Norman Swan: No, we don't. It was first synthesised in 1878, and it's actually a metabolite of a drug called phenacetin.
Tegan Taylor: What do you mean? So that's something that your body breaks it down into?
Norman Swan: Yes, if you took this painkiller called phenacetin, one of the things it gets broken down into is paracetamol.
Tegan Taylor: Phenacetin was an ingredient in Bex, if I'm not mistaken.
Norman Swan: So this is one of the things that Australia was once notorious for, what they used to say to each other when they weren't feeling that well was, 'Why don't you just have a Bex and a lie down?' And Bex contained phenacetin, and we essentially had an epidemic of Bex use, containing phenacetin…
Tegan Taylor: So it was aspirin, phenacetin and caffeine in a tablet or a powder and people were like, yeah, cool, I feel so much better and I don't know why.
Norman Swan: And they'd get the powder in a little packet and throw it down and swill it down with their beer, their whiskey, coffee or tea, and purportedly feel better. And what it caused was kidney damage and kidney failure. And the revelation about phenacetin being so toxic was really promoted by the research of a South African Australian kidney specialist Professor Priscilla Kincaid-Smith, and phenacetin was removed from painkillers in Australia and around the world, and the epidemic of kidney failure went away.
Tegan Taylor: So you're saying if you took phenacetin your body would break it down and one of the compounds it would break it down into is paracetamol. So when we found out that phenacetin was bad, we just kind of skipped the middleman and went straight to paracetamol?
Norman Swan: Kind of. I'm not sure that the how aware they were that it was a breakdown product of phenacetin. Paracetamol in huge doses is very toxic to the liver and can be toxic to the kidneys as well. So it's not free of kidney toxicity, but it's nothing like phenacetin. It's essentially a very safe drug, if taken in the right doses. But the question is, why does it relieve pain? Why does it reduce fever? Because that's not the only thing that painkillers do, they reduce fever as well. And that probably has been used in Bridget, from the sound of Bridget's voice. And they've looked at brain function here, and it may be involved in the endocannabinoid system. But as you said right at the beginning, it's not fully understood. But what is understood is that its effects on pain are not where you feel the pain, they're in the brain.
Tegan Taylor: Is it bad that we don't know how it works?
Norman Swan: I once did an interview with somebody who had found that a certain drug worked in a condition and I asked him, 'What was the mechanism?' And he said, 'Haven't a clue, doesn't matter, it works and it's safe.' A lot of the time when they don't know what the mechanism is they come up with a theory as to the mechanism. But really that's to satisfy people like us journalists, rather than…they don't care, if it works, it works, and it's safe, so what the heck.
Tegan Taylor: All right, well, let's talk about non-steroidal anti-inflammatory drugs, because we do have a better idea of how they work. And of course, we have had this question from Deb asking; which is better, aspirin or ibuprofen?
Norman Swan: Well, it depends what you're using it for. Aspirin is much better for non pain relief. In other words, anti-platelet activity to prevent you getting cardiac problems if you've already had a cardiac problem or a stroke. And the ibuprofen family of drugs are probably better at reducing inflammation than aspirin, because aspirin is probably going to be used at higher levels than ibuprofen. For children, you must not use aspirin. Aspirin is not safe in children, unless you're under strict medical supervision. And the reason is that rarely, a child on aspirin can get a dreadful condition called Reye's syndrome, which is a terribly damaging life-threatening syndrome. So aspirin should not be used in children. It was rare, but not so rare that you wouldn't use it. So most people drift towards ibuprofen.
Tegan Taylor: How does it actually work?
Norman Swan: It works by inhibiting enzymes involved in inflammation called COX-1 and COX-2, and they're inhibitors of these enzymes which are involved in the pathway to inflammation. But that's not the only thing that they're involved with. So, for example, the system is also involved in protecting the stomach against stomach acid. When you take non-steroidal anti-inflammatory drugs, you can reduce the protection in your stomach, not through physical irritation but because you've got the drug in your body, and they can produce stomach ulcers and sometimes catastrophic gastric bleeding. They can also increase the risk of high blood pressure, increase the risk of kidney damage, this is the ibuprofen family of drugs. But 6% of people who are taking nonsteroidals can have an adverse drug reaction.
Tegan Taylor: That's quite large when you consider how available they are.
Norman Swan: That's right. So the risk is relatively low, but you've got large numbers. And the older you are, the more risk you have. So doctors are going to be very careful about prescribing nonsteroidals although you can get them over the counter. If you've got a history of kidney problems, high blood pressure, and you're getting older and frailer, not necessarily good drugs to take. The reason that ibuprofen and another one called diclofenac are on the pharmacy shelves is that they're fairly short acting, so they don't last in your body a long time.
Tegan Taylor: What's diclofenac?
Norman Swan: The common trade name is Voltaren.
Tegan Taylor: It is interesting with things that you can get easily, you sort of think of them as being benign, but they obviously do work to reduce pain. And so it's obviously having some sort of activity happening in the body, which means there could be other activities happening in the body as well.
Norman Swan: Yes, they do work but you've got to be careful. They're not meant for high doses for long periods of time. And that goes for paracetamol as well. If you've got a lot of pain that's going on forever, you really do need to get checked up for it but they don't work on everything. So, for example, on the Health Report, we have in the past referred to Australian research which looks at the effects of paracetamol on back pain and it doesn't help back pain. The other nonsteroidals, the ibuprofen family of drugs, ibuprofen, diclofenac, do have some effect on back pain, but it's not dramatic. Paracetamol is probably better than nonsteroidals for tooth pain. And you yourself might find that you've got a preference. I get migraine, but I'm lucky that paracetamol helps me. So these painkillers don't work for every condition, particularly paracetamol which works on the brain and not on inflammation itself.
Tegan Taylor: One of the things that you often see in advertisements for these sorts of drugs and on the packets is that you shouldn't take them for longer than a few days at a time. And then they always say 'if pain persists, see your doctor'. Is that because you shouldn't be taking them for a prolonged period, or if you're having pain for more than three days, maybe it's more than just a headache or acute back pain.
Norman Swan: It's both. If you've got symptoms that you haven't had before and they're going on for an extended period of time, you need to get it sorted out and find out what's going on. But also, you don't want to be taking these drugs, particularly the nonsteroidals in reasonable doses for extended periods of time, because the longer you take it, the higher the dose, the higher your risk of side effects. And the one side effect I think that I've underplayed is gastric bleeding, you can get disastrous gastric bleeding from a non-steroidal anti-inflammatory drug. So you've just got to be careful about these things and use them sensibly. Ibuprofen is safe in children, it's safe in most adults. I mean, we're not saying that this is a highly dangerous drug, but in a small proportion of people, particularly the elderly, particularly those with other problems, you've just got to be careful or not use them at all.
Tegan Taylor: We're really kind of articulating the potential harms of these otherwise pretty safe drugs today. Can we put it into context? Like, if I've got a headache, or I've sprained my ankle or, I don't know, I'm trying to think of something that's small that's probably a couple of days, I know what the source of the pain is, I just need to hit it. What is the best combo?
Norman Swan: Interestingly, there is some evidence that for pain relief, the combination of paracetamol with another non-steroidal like ibuprofen can be as effective as an opioid analgesic. So if you feel that you haven't had great results from paracetamol, you can actually buy combinations of paracetamol and ibuprofen or other nonsteroidals, which the evidence suggests you do get…still not great for back pain, but for other forms of pain, they may actually be at least as effective as the combinations that used to be freely available of, say, paracetamol with codeine, or ibuprofen with codeine, that the combination of paracetamol and ibuprofen (remember, paracetamol works in the brain, ibuprofen works on the inflammation) may actually not be a bad combination, without any extra harm from…they don't interact with each other. So you're not getting extra harm in
Tegan Taylor: In my N = 1 trials, I find caffeine also very effective.
Norman Swan: Which we've spoken about before. Caffeine is a really important add-on and seems to enhance the effects of other painkillers, yes.
Tegan Taylor: When we talked about caffeine, you imply that there's a situation where using painkillers can actually cause pain.
Norman Swan: That's particularly in headaches, it's called analgesic induced headaches, but it can happen in other chronic pain as well. You've got pain, you use painkillers, and you keep on using them. They're not great at controlling the pain, and you take more and more and more of them. For some reason which is not fully understood, the painkillers themselves can be causing the pain or making it worse. So the treatment, which is very hard to do with people who are psychologically hooked on these and feel that they are relieving the pain, is actually to stop the analgesics. But this is something that really needs to be done with your GP, and done carefully and slowly because it can induce quite a lot of anxiety, but stopping the painkillers can actually relieve your pain.
Tegan Taylor: So a quick recap for Deb; which is better, aspirin or ibuprofen?
Norman Swan: It depends. I refuse to commit myself. For general pain it's ibuprofen or paracetamol. Aspirin should be reserved for the prevention of coronary heart disease and some specific conditions where aspirin is pretty good. But for general pain relief, stick to the ibuprofen family of drugs, those nonsteroidals.
Tegan Taylor: And a recap for Bridget, the Panadol goes into your brain and that's how it controls the pain in the rest of your body. Did I understand that right?
Norman Swan: That's right. So it doesn't go to your sore hip or your sore arm, it goes to your brain and affects your pain perception. And remember, somebody might say, well, is that worse for you than going for an anti-inflammatory? Just remember, the anti-inflammatory drugs like ibuprofen don't change the disease. So if you're taking a painkiller for arthritis, ibuprofen is not going to make your arthritis better, even though it's an anti-inflammatory. It just allows you to get around more and to exercise more. So if you get the pain relief from paracetamol, you're not cheating yourself out of something by not using a non-steroidal, they do not change the course of the osteoarthritis. If only they did.
Tegan Taylor: Indeed. So Norman, we actually got an email…so last week, we were talking about restless legs and we got an email about that that also kind of references what we're talking about this week. It comes from Margaret who said she loved our podcast on restless legs, and she sent us some leg emojis. And then she says she has been plagued by restless legs for many years. Her symptoms seem to be cyclical, but she can't really identify any reasons or triggers for it.
Norman Swan: So what she says is in fact, 'I've tried many things but the most helpful is to get up, do a few stretching exercises and take paracetamol. My GP knows and is happy for me to do this.' And interestingly she says paracetamol doesn't work as a preventive measure, but it does seem to work when she actually has her restless legs. And the reason for Marg writing is to spread the word about what helps for her, which is very nice of her.
Tegan Taylor: Stretching exercises and paracetamol at the time of the restlessness, rather than ahead of time. Any kind of mechanism by which that might work?
Norman Swan: So stretching the legs, getting up and moving, is well known to interrupt the restless legs problem. So the question for Marg is has she tried taking a Smartie or an M&M at the same time to see whether or not it's just the stretching of the legs or if the paracetamol adds to it. But paracetamol is harmless, as you've just discovered in this What's That Rash?, so if you want to try it, have a go.
Tegan Taylor: So you want her to do a placebo controlled trial, but it can't be double-blind because I think she'd be able to tell the difference between a Smartie.
Norman Swan: That's right, and we're not in the business of providing placebos, but M&Ms are more fun.
Tegan Taylor: Well, thank you, Marg, so much for sending that in. And of course if you have any questions or anything that you'd like to tell us, anything at all, you can email us, we're thatrash@abc.net.au.
Norman Swan: We'll see you next time.
Tegan Taylor: See you then.
When you get a headache, what do you reach for? Ibuprofen, aspirin or paracetamol?
Over-the-counter painkillers can be difficult to differentiate, but they do vary, not only in their effectiveness but also in their side effects.
Norman and Tegan talk us through how these drugs work, and which one might be best depending on your situation.
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