ALERT: dextromethorphan

[redbird]

Signal boosting siderea here:

Stop taking dextromethorphan now, it might make COVID-19 more dangerous.

siderea linked to the relevant article with "talk about burying the lede." The finding that dextromethorphan might be dangerous is after lots of "here's this thing we think might help, and that one..." and says that clinical testing is needed before you act on it. I agree with her that no, testing is not needed to stop taking dextromethorphan.

The original article says

Interestingly, a seventh compound – an ingredient commonly found in cough suppressants, called dextromethorphan – does the opposite: Its presence helps the virus. When our partners tested infected cells with this compound, the virus was able to replicate more easily, and more cells died.
Laboratory testing is excellent at generating leads but clinical trials must be done to know if these findings translate to the real world.

This is potentially a very important finding, but, and I cannot stress this enough, more tests are needed to determine if cough syrup with this ingredient should be avoided by someone who has COVID-19.

One thing it doesn't mention is that almost nobody needs dextromethorphan: it's used widely as an over-the-counter cough suppressant, but it doesn't work. It's no better than taking a placebo, and basically a waste of money. (I say "almost" because it has at least one other use, as an adjuvant in a combination pill with quinidine sulfate for pseudo-bulbar affect.)

Comments

[alexseanchai]

thank you

[pameladean]

Yikes! Thank you. When I think of the effort I went to to get some syrup with dextromethorphan in it. I can't actually take it myself, since it gives me tachycardia like whoa, but I still thought it was generally useful. Urgh.

P.

[anne]

Well, shit. It's the only nondrowsy cough suppressant I know of, and I can't take the drowsy kind at work. Not immediately relevant...but allergies make me cough and talking makes it worse. So that's going to be a bad trade when I go back. (And placebos work, is the thing. I don't care if I'm fooling myself, as long as I'm not coughing too hard to give a tour.)

[dewline]

Well, that rules out a lot of brands I've trusted.

[otter]

yikes indeed. I haven't been able to take cough medicines for decades - they don't mix well with my psych meds to begin with. But I certainly won't start now.

[st_aurafina]

It's not my favourite cough suppressant to recommend for lots of reasons but that's a good one to add to the list.

[adrian_turtle]

Yeah. It reminds me of children's aspirin--when I was a kid, everybody knew it was a safe and effective way to bring down fever when a child had flu or chickenpox. Then they realized it could cause Reyes Syndrome, and by the time I was old enough to babysit you Just Didn't use it that way.

[adrian_turtle]

Honey actually works slightly better than placebo, for toddlers. They compared no treatment, honey, and a date-syrup placebo, and counted coughs rather than just asking the parent if it helped any. That might be worth a try, though I don't think it's been tested in adults.

What I find most effective for dry coughs is Sucrets. They taste horrible and turn my tongue bright red, but they get my mouth and throat numb for hours. It might take a little practice to speak clearly without feeling exactly where your tongue is, but it could be worth it on the days when you aren't on good terms with your throat.

[calimac]

This was the first I've heard about dextromethorphan being ineffective as a cough suppressant. Upon looking it up I find that the studies saying so are at least 7 years old, so why hasn't this news been more widely disseminated?

[anne]

Thank you, I'll try both of those! And local honey is supposed to be good for allergies anyway, because of the pollen.

[gingicat]

That explains why Mucinex-D made me feel worse! Edit: no, it doesn't. Hmm.

[redbird]

Separate from this I've seen a lot of advice to get pills/liquid medicines that contain only one thing, to help keep track and avoid overdosing, though that's mostly from concern about acetominophen (Tylenol). I also remember reading a "who even thought this was a good idea" article about the common dextromethorphan+guaifenisin medications, pointing out that few people need the cough suppressant and the expectorant, i.e. cough promoter, simultaneously.

Avoiding multi-ingredient pills strikes me as good advice in general, i.e. unless there's specific reason to combine them. The only combo pills I have right now are Canadian painkillers and muscle relaxants that are over-the-counter (possibly with pharmacist consult required) in that form, but contain an ingredient that requires a prescription by itself, both here and in Canada. (Acetominophen+codeine works better than either ingredient by itself, and there are combo pills for things like HIV; the main reason for the warning about those cold/flu/allergy mixed pills is that multi-ingredient pills are an identified risk factor for acetominophen overdose.)

[redbird]

At a wild guess, because there's an awful lot of inertia in medicine as actually practiced, and companies that profit from people thinking dextromethorphan works. CVS cheerfully stocks homeopathic nostrums on the same shelves as things like Robitussin DM.

[calimac]

But I know that homeopathic nostrums don't work. Nobody's hiding that information.

[redbird]

My thought is, the same drugstores that stock homeopathic crap because "the customers want them" and don't say "are you sure you want this? X product is just as safe and works better" either don't know or don't care that it's crap, because capitalism gives them a reason to ignore that and take the money. And then the customer sees something labeled "cough suppressant" on the shelf and assume that it does what it says on the label. *sigh*

And the slightly more cynical or educated shopper (who knows that "homeopathic" isn't Latin for "natural" or "herbal") thinks "Airborne is useless crap, but my doctor suggested Robitussin" and buys some. *sigh*

Less cynically, there's a LOT to keep up with in medicine; a pediatrician will tell parents not to give dextromethorphan to children under 12 because it's not safe for them, but may not have been told that there's no reason to give it to anyone. A safety campaign that includes relabeling packages as "under 12: Do Not Use; 12 and over, X amount every four hours, no more than 4X per day" strongly suggests that this is real and useful medicine.

[adrian_turtle]

One possible explanation for a cough suppressant making you feel worse:
you had gunk in your lungs, and coughing it up was good for you.

Another possible explanation: the Mucinex didn't make much difference, you just took it when you were on your way to getting worse.

Someday there will be vaccines and tests and we'll be able to think about symptom relief for sicknesses that aren't (definitely aren't!) COVID.

[athenais]

Well, so much for the placebo effect. Now I can't take it knowing it doesn't really work. I rarely take it anyway, I'm usually a "suffer through it" kind of gal because I never had any medications at all growing up.

[conuly]

Somebody thinks they work or they wouldn't buy them. And this cough medicine knowledge isn't "hidden" either - so long as you know to look.

[conuly]

IIRC, the -D has the same sort of effects as benadryl, that is to say, long term use is associated with higher risk of dementia and it should be avoided by seniors altogether.

So maybe it does?

[redbird]

Somebody thinks they work, yes.

I read that a lot of shoppers think that "homeopathic" means "herbal" or "natural," not "diluted until there's unlikely to be even one molecule of the claimed ingredient." So while it's likely that at least some of the people selling homeopathic nostrums believe in homeopathy, many of the customers don't.

[calimac]

But if you don't know to look, it is hidden. And as my previous examples were there to show, often enough this news gets around. I've heard plenty of stories over the years of one promoted nostrum or other than turned out not to work. This one is pretty obvious and straightforward, and yet it didn't get passed around. Until years later, in a blog.