Molecule of the Day

Niacin (Nicotine vitamins?)

Niacin is also known as Vitamin B3. Interestingly, it’s also called “nicotinic acid,” and the similarity of the name to “nicotine” isn’t coincidental:


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Take a look at nicotine and you’ll see the structural similarity.

Interestingly, high doses of niacin have been noted to modulate cholesterol (hundreds of times the RDA). A few problems can occur, though – the most common is prostaglandin-mediated flushing of the face. The most serious are heart and liver problems.

Merck was going after a cholesterol drug that incorporated niacin, with a prostaglandin blocker to mitigate the side effects. Modulating prostaglandin metabolism isn’t without tox liability – this is what Vioxx and other COX-2 inhibitors were monkeying with. However, this strategy was essentially working later in the game – not inhibiting prostaglandin production, but blocking those that are produced.

Today they got their not approvable letter for this drug, so there were obviously some (unspecified) concerns.

The COX-2 agents caused everyone to take a second look at the class, to the point where we’re questioning even the OTC NSAIDs (except aspirin). A prostaglandin antagonist isn’t a COX inhibitor, but some people are gun-shy about the whole pathway now. Additionally, theres the liver tox liability – cholesterol biosynthesis occurs in the liver, so you’re altering liver function with these drugs. This is why you come back to the doctor for blood tests when you’re on statins (and you can’t just use an OTC cholesterol test). Since niacin is known to sometimes cause liver problems (although usually with “extended-release” niacinamide), that could be the issue.

[The author is not a physician and holds no Merck position].

Comments

  1. #1 azmanam
    April 29, 2008

    Derek Lowe wrote a post about Merck’s use of niacin and its formulation in Cordaptive as a cardiovascular drug:
    link

  2. #2 Gatsby Blastyn
    April 29, 2008

    So what you’re saying is, it’s time to take out that pack of smokes and burn a few down. Right?

  3. #3 NJ
    April 29, 2008

    The prostaglandin-mediated flushing of the face (and arms and legs and torso) I could handle. The 10-15 minutes of convulsive itching of the extremities? Not so much.

  4. #4 Uncle Al
    April 29, 2008

    When did American healthcare transition from “live well for a reasonable lifespan” to “horribly live as long as possible?”

    You will die. Go out with a smile and well-ripened brie on your chin. Nobody ever got hunger pangs for oat bran.

  5. #5 arthritistreatmentguy
    April 30, 2008

    talk about nicacin. I used to put topical niacinamide gel on my face to ease out acne.

  6. #6 Andrew
    May 1, 2008

    High dose Niacin was used as a do-it-yourself anti-psychotic around the 1960s, apparently with considerable success.
    I’ve personally used slow-release niacin (NOT niacinamide) with other B-vitamins to treat and eventually cure a former girlfriend’s hypoglycaemia, which had schizoid symptoms, and also used it for myself for stress (until the Australian government made high dose niacin “prescription-only” and forced it off the market – now I take govt subsidized Prozac).
    It’s also been considered a (blood?) detoxifier, and it’s my understanding that Scientologists use it in their “Purification Rundown” to allegedly flush out radiation damage, both nuclear and solar. The “niacin flush” allegedly matches the pattern of past sunburn for example, missing areas protected by bathing costumes.
    I suspect that most, if not all, of the cases of niacin liver toxicity were due to semi-informed people going off half-cocked and using high dose niacin (or worse, niacinamide) without also supplementing the other B vitamins (B vitamins are synergistic, and using high doses of one without the others is asking for trouble).

  7. #7 Bill Barton
    November 14, 2009

    Is it possible for coninine (nicotine) to show up in the blood sample after taking 2 Gms of niocin per day for 6 or 8 years. I have never smoked and coninine showed up in my blood sample for Lifr Insurance.

  8. #8 patzy
    May 30, 2010

    Uncle Al, I agree. We do all these things to add 20 years to our lives and then suffer through old fragile age and diseases. That isn’t living, it is enduring.

    It is quality of life not quantity that is important.:)

    I’m not going to drink or smoke because I don’t like either but I’ll have my ‘treat’s when I want them.