What's the Straight Dope on cough suppressants

OTC there’s dextromethorphan, which is available most readily in stuff like Robitussin DM (and as far as I know, also in Hold brand cough drops).

And of course prescription stuff involving codeine, typically in a syrup.

I keep hearing that dextromethorphan may not even really work. Any strong evidence either way?

Similarly codeine, when I’ve been googling it, some studies show it doesn’t do much. Has it every been formally studied to prove it suppresses cough? My google-fu is not turning up anything conclusive.

My own anecdotal evidence: 24ish years ago I had mycoplasm bronchitis which caused severe, eyeball-popping, shoot-me-now-so-I-can-rest coughing. DM didn’t touch it. Of course neither did the codeine cough syrup. Hell, if someone HAD shot me my corpse would probably still be hacking like an 80-year-old chain smoker. But now, I’m on a medication that has “dry cough” as a side effect, and I had a luuuurvely few days cough-free while I was on Good Drugz (morphine then oxycodone) after surgery. The cough returned with a vengeance the day I stopped, sigh… obviously some discussion with the doc will be happening soon re that.

I was under the impression that codeine was more for pain, rather than suppression. It was just that the lack of pain made it easier for you to not feel like you needed to cough.

Codeine works so good, you never want to leave it. I think of it as “it makes the coughing stop, but it’s also like being moderately drunk. With no hangover”

Of course, it’s prescription only, so you have to leave it.

:smiley:

For me, the OTC cough suppressants (Dextro) work ok. That’s not proper evidence, but I do think it does work for me.

Tussionex (codeine and an antihistime) works wonders for me. I take about a half a dose and and my cough goes completely away and I sleep like a baby.
BigT, I haven’t heard of that, but even if that is the case, it still works for me.

Oh, so much, where do I begin?

Yes, Dextromethorphan (DXM) does work, it, and all the opiates, work on the cough center in the Medulla in the brain. It lowers the impulse needed to cough, making it so you don’t cough as much.

Yes, Codeine acts on the same center of the brain as DXM in order to suppress the need to cough. Codeine was actually the common cough suppressant given until the discovery of DXM. In fact, one of the main reasons that DXM is OTC for cough is because of the fact it is not addictive like codeine is.

“Dry Cough” as a side effect? Sounds like you might be on an Angiotensin Converting Enzyme (ACE) Inhibitor. These do have a dry cough as a side effect, normal cough suppressants like DXM and Codeine are not very effective against these types of cough. However, the stronger opiates do affect the cough center in the Medulla stronger, so could override the cough caused by a ACE-I. However, if that is what is causing your cough you should get your doctor to change you to a Angiotensin Receptor Blocker (ARB) instead.

Codeine was the normal OTC anti-tussive before the discovery of DXM. When DXM was discovered, and they found it had about the same efficiency as codeine has, is when codeine became mainly a prescription drug. However, DXM has no effect on the opiate pain receptors in the brain, unlike codeine. So, codeine is effective against the cough center and for pain, while DXM is only against the cough center.

Actually, that’s not totally true. Codeine when mixed with another drug is a federal Schedule-V drug. However, it has an exclusion where in can be sold OTC as a cough suppressant if the state laws allow it. In my state (Georgia), it is legal to sell Robitussin AC (Codeine and Guaifenesin) in 4oz bottles. Limit 1 bottle per a person per 48 hours… However, most pharmacists won’t sell it to you unless they know you.

Tussionex is actually Hydrocodone, not Codeine. It is a stronger opiate then Codeine is (It’s the same opiate that’s in Vicodin and Loratab). Oh, and the antihistamine is chlorpheniramine for the record.

DXM only works for me if I take a much higher dose than on the label and if I go too far I start getting a little spacey.

Though I’ve heard that DXM can be addictive in some people, or at least it can be used recreationally in high doses, I assume that reasonable occasional OTC use is not an issue.

Got it in one! At first we thought the dry cough would prove to be no more than a minor annoyance and I could live with it but it’s progressing and disrupting my sleep. I’ll be visiting the doctor soon to discuss a switch. Obviously a nightly Percocet is not likely to be the solution! I did take one OTC DXM/guaifenesin last night at bedtime and dunno if it helped; I only had one “wake me up, hack up a lung, pop some stitches” episode (as opposed to 2 the night before) so who knows if it made a difference.

BTW - the question about DXM’s efficacy is from numerous sites:

Cold medicine - Wikipedia (that link suggests I should instead eat a dark chocolate bar at bedtime, which sounds pretty nice :slight_smile: but that’s going to cause other sleep issues)

Something similar on codeine - though I see in the abstract both of the NIH links talk about effectiveness in dealing with cough from respiratory infections vs. “chronic and induced” coughs. ACE-induced coughing would seem to be the latter, I guess.

Yes, it can very much be used recreationally at high doses, but I hadn’t heard of it being addictive.

Dunno how common, but there appear to be some cases of at least mild addiction - whether it’s a psychological one or a true physical dependence, I don’t know. Cites:

http://www.helium.com/items/161950-addiction-to-cough-syrup-dxm (warning: commercial with sound plays in the sidebar)
http://www.msnbc.msn.com/id/4608341/

I’m not even remotely worried about dependence with reasonable OTC use of course. And since I have yet to “enjoy” the buzz I’ve gotten with medical use of narcotics, I doubt I’ll be experimenting with “robo-tripping” any time soon!

Recreational != addictive. I don’t think there’s any evidence that dextromethorphan is physically addictive. (Psychologically, maybe, but then again, any behaviour has the potential to be psychologically addictive.) In higher doses it’s a dissociative, like nitrous oxide. Addictive drugs tend to be euphoria-inducing stimulants and depressants, like methamphetamine or alcohol.

Consumer Reports does this at least every other winter and always comes back with OTC cough meds don’t work any better than plain old water and that water with lemon does a better job than plain water or cough medicine.

Of course this is OTC only.

I guess the old remedy for coughs, two teaspoons full of honey, lemon and whiskey has some validity.

How do they determine whether a cough medicine “works”, though? Are they measuring time to recovery, or just counting coughs? If the former, cough medicines aren’t going to be found effective; they’re meant to suppress coughs, but they don’t cure the underlying condition which makes you want to cough in the first place.

Also, there are a couple different kinds of cough medicines. There are cough suppressants, like dextromethorphan and codeine, which are supposed to be used for dry, unproductive coughs. And then there are expectorants, like guaifenesin, which break up the mucous implicated in chesty coughs. They don’t actually suppress the cough reflex, but rather work on the idea that you’re trying to cough up all this mucous and phlegm, so by breaking it down, it helps you get rid of it and thus reduce your impetus to cough.

A quick update on that comment: I phoned the doctor’s office last week, on one of the days they were in (snow = crazy schedules), and left a message saying essentially “lisinopril coughing becoming intolerable, can you phone in a change before our next visit” (which is in 3 days). I assumed the message got lost in the shuffle but got a call from the pharmacy 3 days later saying my scrip was ready. It turned out to be not an ARB, but cough syrup with codeine. Ooookay - well, not a long-term solution obviously but it would keep me from hacking up a lung in the interim. And, it actually does the job (DXM didn’t touch the cough). Possibly if I were on a higher dose of the ACE it might not be sufficient.

Anyway, hopefully it’ll all be moot in 3 days. And fortunately the syrup is nasty enough that it’s a disincentive to develop a habit!

This isn’t really going to be a GQ-standard reply (i.e. no actual cites), but I’m throwing it out here for what it’s worth anyway. A couple months ago when I had a really bad cough that wouldn’t stop no matter what I used I did some Google research on the different OTC medicines and found links to some recent studies in medical journals which, according to the abstracts (which were all I could access without a login), found no evidence that any of them actually worked. Though the codeine may be useful at night to help you sleep, if the cough is keeping you up.

And then when I gave up and went to my doctor for antibiotics to kill the thing that was causing me to cough, I mentioned to her that I’d been through a whole bottle of cough suppressant and she said “those don’t really work anyway”.

As I said, take it for what it’s worth.

I had such bad coughs during the Winter when I was in 7th grade(1990 or so), the doctors prescribed codeine for me.

In my opinion, it was the only thing that really worked. However, like others have said, it sent me to a wonderful dream land where I was high as a kite and happy as can be. It seems like it could be addictive to me.

Otherwise, very little helps.