NAC makes me vomit
December 30, 2010 4:50 PM   Subscribe

I'm in a research trial testing if N-acetyl-cysteine (NAC - an antioxidant) has a beneficial effect on mood (etc.) I started taking the NAC last night (on an empty stomach), and vomited twice upon awakening. I just had another dose, with lunch, and vomited again. I feel fine apart from this, and I read that NAC can cause nausea / vomiting. Should I keep on trucking, i.e., will my body get used to the substance? The research clinic is closed until second week of Jan!

The dose is 1000mg, twice per day. First dose was last night. This morning, I woke up with a horrible headache, so I drank a large glass of water, thinking I was just dehydrated. Following this, was when I first vomited.

Is that strange that my body waited the whole night to vomit up the NAC?

After vomiting, I feel great, no headache, no nausea. The researcher did tell me in my initial interview that headaches are pretty common at first with NAC, but she didn't really mention vomiting so I am not sure whether to keep on trying this? Or cease taking it until 2nd week of Jan, when I can contact the clinic.

I assume / hope my body will get used to the NAC, and stop puking it up? I actually want to keep on going with this, because I am interested in high doses of antioxidants, and would love to see if they have a positive effect on my health.

Since I vomited this morning's dose, ought I try another? Is there any reason not to try this out, if I feel fine apart from vomiting?
posted by anonymous to Health & Fitness (21 answers total) 2 users marked this as a favorite
Or cease taking it until 2nd week of Jan, when I can contact the clinic.

Call your doctor. I think it is unethical for them to not be reachable when you are taking a medicine.
posted by Ironmouth at 4:55 PM on December 30, 2010 [17 favorites]

There has to be another way for you to get in touch with the researchers. Many times doctors work at several different places. I would try googling their names to see if you can get some alternate contact information. They should have given you some kind of instruction about what to do if you experience a side effect like that.
posted by amethysts at 5:01 PM on December 30, 2010

Don't do a medical experiment if no medical supervision is available. Stop taking it, get back to them when they're open and then discuss if they want you to do the trial when they are around to supervise and advise.
posted by L'Estrange Fruit at 5:04 PM on December 30, 2010 [1 favorite]

Are you sure there isn't an emergency contact number somewhere? I would look through whatever paperwork/documentation/instructions they have given you as I would be shocked and horrified if there isn't an after hours contact number.
posted by goshling at 5:05 PM on December 30, 2010

Do you even know you're actually on the supplement— ie, is it open label or could you even be on placebo? Also, agree with others that there must be an emergency contact info somewhere or the trial is unethical.

Finally, you do know that most of the research on antioxidants has either found no effect or actual harm from mega-doses, right? [Link goes to ben goldacre's debunk of a purveyor, with summary of research].
posted by Maias at 5:11 PM on December 30, 2010

Second all of that. Your informed consent form had to have listed a 24-hour contact person (if this is in the US): call them!
posted by hammurderer at 5:32 PM on December 30, 2010 [1 favorite]

The only thing I've ever used NAC for is to stop liver failure after tylenol overdose, where it's both unpleasant to take and ridiculously expensive - but lifesaving.

This trial sounds really suspect and if it's making you throw up I'd be quitting immediatly.
posted by Silentgoldfish at 5:39 PM on December 30, 2010

I have never heard of a legitimate clinical trial that didn't provide 24-hour contact coverage for subjects. Yikes!
posted by Sidhedevil at 5:46 PM on December 30, 2010

Stop taking it and wait until the clinic is open. You shouldn't be doing a drug trial without being able to call the clinic for help.
posted by Chocolate Pickle at 6:07 PM on December 30, 2010

(Silentgoldfish, I'm guessing the researchers are screwing around with the glutamatergic properties of NAC, in the same way that memantine has become a popular object of neuropsych research for its NMDA receptor antagonist features.)

OP, you need to call your GP or otherwise get with someone about this before you take any more of it. Certainly throwing up your first two doses has already messed with the data in your case, so you can't really screw up the science any more and may as well get help.

I've had that stuff before and it's no picnic, but throwing up right off the bat like that can't be pleasant or helpful for you.
posted by fairytale of los angeles at 6:29 PM on December 30, 2010

I have never heard of a legitimate clinical trial that didn't provide 24-hour contact coverage for subjects.

Neither have I and I work in biomedical research investigating food components and supplements (i.e. I work with people who run these kinds of trials). There is no way any reputable trial would get ethics approval or FDA clearance without providing proper medical supervision, and if they really are closed and unreachable for several days then this trial is not one you want to be part of. You're having pretty bad side effects, you *have* to be checked out. Also the trial supervisors should really want to know about this side effect asap, it has direct impact on their findings in several ways (not just the safety aspect). Examples, they don't know what active dose you're getting if you're throwing up sometime after eating it, and if really is slowing your stomach transit times you may end up absorbing more than expected rather than less. This kind of thing is very relevant to whatever end point they're measuring. The continual supervision isn't just to stop you getting hurt, it's necessary for the trial results to be at all valid.

If you're actually looking for therapeutic effect then safety trials should have been done first. Either this side effect was unexpected, in which case it's actually kind of a big deal for the reasons I mentioned above, or it was known and somehow not gotten across to you, which brings us back to bad science.

Oh, and if you're taking a large dose of something with the expectation of pharmacological effect then it's every bit as scary and important as any artificially made drug, regardless of if it's a food supplement or something "natural". If they're not running this like a legitimate clinical trial because they're testing a "supplement" then it's not going to get scientifically valid results and is not worth your time or possible health damage.
posted by shelleycat at 6:33 PM on December 30, 2010 [15 favorites]

You will need to consult your primary care physician or an ER if when you go off the drug - and have the bill sent to the study - going off of a mood enhancer can cause some serious side effects all its own, including suicidal thoughts and manic episodes.

Utterly irresponsible for them to be unavailable. Inexcusable.
posted by Slap*Happy at 7:05 PM on December 30, 2010 [1 favorite]

call the clinic--they may (should) have an answering service that can put you in touch with an on-call clinician. if not, stop taking the drug and call your regular doctor.
posted by thinkingwoman at 7:42 PM on December 30, 2010

I came here to say what shelleycat said. The researchers would not want you to keep taking it if it makes you sick, both for ethical reasons and because they won't be able to include you in the study results anyhow, not knowing what dose you actually kept down. (I am such a researcher.)
posted by Knowyournuts at 8:47 PM on December 30, 2010

I took NAC and felt a little nauseated but not to the point that you are. It didn't work for my mood, so I stopped taking it.
I think that the negative effects you are experiencing sound like they are outweighing any positive mood benefits. Since it's just a supplement, you won't lose anything by stopping it now and starting again once you can ask your doctor about it.
posted by rmless at 9:12 PM on December 30, 2010

Stop taking it. Tell the contacts why you did. They'll want to know what percentage of people don't tolerate NAC.

If it's a paid trial, you'll still get paid.

This is an important part of clinical trials - if a number of patients/subjects don't tolerate the substance, then, it's not going to be a good treatment. There are probably a number of other people in the trial who are are reacting in a similar manner as you are.
posted by porpoise at 9:18 PM on December 30, 2010 [1 favorite]

If you're reacting poorly to it, stop, but NAC isn't exactly an experimental compound. It's a glutathione precursor that's available over-the-counter. A common use is to minimize hangovers by helping replace the glutathione that gets used up to metabolize alcohol.
posted by dws at 9:40 PM on December 30, 2010

Nthing STOP. You could be seriously hurting yourself.
posted by Citrus at 6:50 AM on December 31, 2010

NAC isn't exactly an experimental compound.

Doesn't matter. Proper monitoring is every bit as important for a known, understood compound as it is for an experimental one, particularly given these specific side effects (throwing up an orally dosed compound can invalidate everything). Best case scenario here is a fairly large breakdown in communication where information about after hours care and how to deal with what sounds like a pretty common adverse effect was somehow not conveyed to the OP. Informed consent is specifically designed to avoid such an issue (this information would have to be both verbally explained and given in writing for trials run here) so someone has dropped the ball. If there really is no monitoring then the whole trial is suspect (at best), regardless of what they're testing.
posted by shelleycat at 3:10 PM on December 31, 2010

1000 mg 2x a day is a lot of NAC. Although its "natural", it is a serious and potent substance and should be considered like any other medicine. If you were taking high doses of ibuprofen and started vomiting, you would stop. Same deal here.
posted by blargerz at 6:10 PM on December 31, 2010

Mod note: From the OP:
I wish I had come in earlier, because I'm paranoid now that I have in some way made this research clinic (which is highly reputable) identifiable and that their image might be harmed. Unfortunately I couldn't locate this question on the green until just now, so I thought for some reason my question had been rejected?

This situation was a misunderstanding, on my part. While yes, the research brochure had 2 phone numbers to call in case of side effects, both numbers were unattended at the time, and I neglected to leave voicemails. I called the main reception at the clinic and heard a recorded message about the office being closed until mid Jan. Thus I assumed they wouldn't check their voicemails, but if everybody is saying it would be utterly unethical if they didn't -- then I am sure they are ethical and would have contacted me asap if they heard my message.

I did email my contact and she got back to me by the end of the day (and very apologetically so). They are concerned (and surprised -- for good reason. They haven't had this side effect before) and have (as you all suggested) told me to cease taking it.

Never fear everybody, there are no shoddy research clinics, just silly research participants like me. PS this study is in no way suspect; I deliberately altered the details of the experiment a little to make sure this was truly anonymous.

All this said, I am amazed that I had such an odd reaction to this substance. I have an iron gut! And yes I very well may be on placebo, but do placebos cause vomiting?

Thank you all for your sound advice to stop taking something that my body is obviously rejecting (even if my body is being utterly illogical! grrr)
posted by jessamyn (staff) at 7:37 AM on January 1, 2011

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