Putting Salonpas in the Firing Line

I feel like I've recently been bombarded with slightly cringe-worthy adverts for pharmaceutical products. And no adverts annoy me more than those for painkillers which claim to be delivered "direct to the source of pain" or similar. 

When I was a wee bairn, I remember being interminably confused by how one particular glug of Calpol will know that this time I have a headache, so it has to go to my head, whilst the next dose knows that it is required to report for painkilling duties in my ear because I have an earache at that particular time. Now of course, I have a more thorough understanding of pharmacokinetics (or at least I should have, but most of it has probably been pushed out of my brain by less useful, but inordinately more entertaining things), and I know that this is all total nonsense. A drug is distributed around the body depending on its properties, and whether it needs to go "direct to the site of action" depends on how it works, and whether it acts centrally or not.

I now spend a percentage of my time on locum shifts advising people that topical painkillers like Ibuleve and Voltarol are probably no better than taking tablets, and attempting to steer them towards the more effective-and cheaper- option of ibuprofen tablets, with advice to just rub the area if that makes it feel better, as that's what makes topical preparations work. So I'm already set to default to cynical mode with topical pain preparations. 

Enter the newest shiny painkilling gimmick onto our screens: Salonpas, a patch which, according to the US website allows absorption of the active ingredients through the skin to "go directly to the pain site"

So my skeptical ears are already pricked up. A quick glance at the website offers me a video to tell me how it works, which also makes me suspicious. I also can't find any particularly robust evidence on the website with a cursory look. 

The other thing that's worrying me is that these patches are rather expensive. they appear to retail at £4.99 for 3 plasters, with the maximum dose being 1 patch twice daily. That would be a whopping £23.29 per week.

So I'm going to start having a bit of a dig about to see what evidence there is on this new product and i shall, of course, let you know the results. It could well be that these patches are worth every penny, and are the holy grail in pain relief. However I suspect they're just another way to get money from people who are pretty desperate. But, I will remain open minded in my quest for evidence-based information. 

Salonpas, be warned. I'm after your evidence.