My generic aspirin says it’s caffeine-free and sodium-free on the label. Why would they be in there in the first place?
Should I seek out some caffeinated salty aspirin?
Quite a few pain killers contain caffeine. I know its in BC Powder.
Just checked. Yep.
Caffeine apparently has some analgesic effect of its own, so lots of aspirin type medicines have it.
Dunno about sodium, but caffeine acts in concert with aspirin or acetaminophen to combat pain more effectively than either analgesic alone.
The entire reason for the existence and heavy long-term advertising of Excedrin is that is adds caffeine to otherwise generic aspirin and acetaminophen and so can sell for many times the price.
Exapno, it also helps build a loyal clientele out of people like me who can’t tell the early stages of a migraine from a caffeine withdrawal headache. 
Caffeine is an analgesic adjuvant. Studies show it does make aspirin, and other pain relievers, more effective.
Not sure what role sodium plays, but it probably stabilizes the compound.
Wow, I never knew that: I always just assumed, in my cynical way, that adding caffeine was just a bit of a cheat to make people feel perkier and therefore impressed that their aspirin worked, and thought I was being very smart and clever to stick to cheap generic aspirin. More ignorance fought, then.
Another nine-dollar word you’ll run into for this is that caffeine will potentiate the analgesic. In other words, it has a synergistic, or multiplying effect on the effectiveness of the aspirin or whatever the base painkiller is.
I suffer from something called atypical migraines. My mom, sister and uncle get them as well. The only thing that helps us is Excedrin. That stuff is a life saver. There is a generic form of Excedrin by the way. It’s called EPF or something like that. They stock it in the medicine cabinet at work.
Interesting, since Excedrin went to great lengths never to make that claim, and you’d think they’d be shouting it out.
Their claim was that the caffein may make the aspirin more effective, not that it did.
The sodium is usually present as part of a filler compound; something that’s in there to help add bulk, or a binding agent, or whatever. In many formulations, the chemists had a choice of creating the pill with various types of salts, either sodium-whatever, calcium-whatever, magnesium-whatever(2), etc. Offhand, I’m not comfortable giving actual examples used in pharmaceuticals, since I’m very tired and I don’t want to make a mistake!
If the stability/bioefficacy/clinical etc testing showed no particular difference between one formulation or another then they might choose to go with the one without sodium, since sodium has associated health issues (keep in mind that many, many different versions of a drug might be tested… I once worked on a project where they were weeding it down to one marketable pill from 12 different recipes, only varying in the non-active ingredients!)
A similar thing goes for lactose; if you can make your pill without it, then the very, very very few people who react badly to such a miniscule amount of lactose become possible customers. Being lactose-free also makes it easier to certify the pill as being kosher, though most companies never bother doing so because of the cost and PITA involved, unless the drug ends up OTC… there’s some value to that.
I had always heard that the caffeine expands your blood vessels and makes the pain reliever move through them faster. Is this incorrect?
Valete,
Vox Imperatoris
Is it only the pain-relieving properties of aspirin that caffeine affects? (What happens if someone is taking aspirin for “heart health”?)
Exactly opposite. Caffeine is a vasoconstrictor.
Not exactly. But what you said in the next sentence is closer to the mark:
Aspirin is acetylsalicylic acid, a modified form of salicylic acid (which is found in willow bark). However, the acid by itself is not very soluble, so to make soluble aspirin, it is sold as the sodium salt, sodium acetylsalicylate, which is much more soluble in water.
Normal, non-soluble, aspirin, however, wouldn’t normally have sodium in it anyway, so I think it’s just marketing.
Is the sodium salt more stable than the acid?
Also, even in non-soluble aspirin wouldn’t a higher solubility increase the uptake of the drug and speed its effects?
I think the sodium salt would be less stable. The acetyl group will hydrolyze under mildly basic conditions. Also, once it gets to the stomach acid, it’s as good as protonated. Maybe there is some small absorption difference, but I suspect it gets protonated the instant it hits the stomach. Using the sodium salt may make it more comfortable to take as it travels to the stomach.
I looked for evidence that they used sodium acetylsalicylate, but couldn’t find any specific formulation that said they did. I suspected that Bufferin did, since I assume the name is derived from acid-base buffer which is what the salt would be if it were partially protonated.
I was thinking stability in storage rather than when it’s taken.
Yes, that’s what I meant. Like I said, your stomach is acid so not mildly basic. The real problem would be humidity. As for other decomposition processes, I have no idea.
ETA: I think my paragraph structure is confusing in the first response.
When I was a kid (back in the 50’s), my dad was in the military and we would often go to the base hospital for any kind of medical treatment.
I remember for various aches and pains they would give us pills called APC. I know the “A” and “C” were for aspirin and caffeine (or maybe codeine?), but I’m not sure what the “P” stood for.
Also, I don’t know if this was common medicine at the time, or if it was mostly used in the military, or why it’s not common any more. I’m assuming that acetaminophen and ibuprofen have supplanted its use.
Anyone else remember using APC for pain relief?