Why does my niacin medication make my skin itch?

[Tess of the Derbyville]

I couldn't tolerate statins so my doctor put me on a time-released form of niacin to lower my cholesterol. So far so good - my count has come down and I've had no side effects to speak of, except for an occasional intense itching mostly on my legs and back. This happened when I first started taking the medicine, whenever my dosage has increased, or sometimes for no reason at all.

It seldom lasts more that a day or two and isn't so uncomfortable that I want to stop taking the drug, so my doctor says not to worry about it. Still, it seems like an odd sort of side effect. I've looked in various reference books, and while they may list itching as a side effect of niacin, none of them explain why. Does anyone have an answer?

[Nametag]

Originally Posted by Tess of the Derbyville

I couldn't tolerate statins so my doctor put me on a time-released form of niacin to lower my cholesterol. So far so good - my count has come down and I've had no side effects to speak of, except for an occasional intense itching mostly on my legs and back. This happened when I first started taking the medicine, whenever my dosage has increased, or sometimes for no reason at all.

It seldom lasts more that a day or two and isn't so uncomfortable that I want to stop taking the drug, so my doctor says not to worry about it. Still, it seems like an odd sort of side effect. I've looked in various reference books, and while they may list itching as a side effect of niacin, none of them explain why. Does anyone have an answer?

Niacin is a potent vasodilator, and causes severe flushing. IANAD, but I suspect it's related to that.

[Stark Raven Mad]

It doesn't give me itches at all, but makes all my veins pop out, which is cool.

[Grossbottom]

I don't know, but I overdosed on niacin once, due to an idiot roomate putting her prescribed niacin in an aspirin bottle. Thinking they were aspirin, I popped a few of them and went on about my day, and an hour later was convinced I'd been inexplicably hit with a chemical weapon attack.

[KarlGauss]

Niacin, also called nicotinic acid, is actually a terrific drug for abnormal cholesterol and/or triglyceride levels. Indeed, niacin will tend to improve things regardless of the particular cholesterol or triglyceride abnormality that someone has. It is also an inexpensive drug. So, it's a shame that it has a number of side effects - most of a nuisance character, but some more serious.

Niacin causes the body to release a chemical called histamine. Many of niacin's side effect are due to this histamine release. These include itching, flushing, ulcers, and even low blood pressure.

Histamine is the same substance (or, at least, among the substances) released at the site of mosquito and other insect bites. Locally, it causes itching. In higher amounts, and when released more generally throughout the body, effects like those mentioned above become apparent.

As an aside, you may be familiar with drugs like Zantac, Pepcid, or Tagemet. They are used to treat and prevent stomach/small bowel ulcers and belong to the class of drugs called histamine-2 receptor anatagonists. That is, they block certain of the effects of histamine. With respect to ulcers, histamine causes acid release in the stomach. Blocking histamine with H2-blockers, therefore, makes good sense and there's lots of evidence that they work well in this regard. With respect to Niacin, since it causes histamine release, you'd expect it to promote ulcers - which is exactly what can happen (not too frequently, mind you) in people taking it.

[Zsofia]

My dad's niacin pills made him absolutely miserable at first. He takes a lot of medication and is not in the absolute greatest of health, so that first day he thought something was really terribly wrong! He gets very hot and itchy. I think now he takes ibuprofin? or something, a while before the niacin, and that helps a lot. (On his doctor's advice, of course.)

[Qadgop the Mercotan]

What KarlGauss said. In addition I tell my patients on niacin to take aspirin (if able) about an hour before their niacin, it reduces the flushing.

[ShibbOleth]

Originally Posted by Qadgop the Mercotan

What KarlGauss said. In addition I tell my patients on niacin to take aspirin (if able) about an hour before their niacin, it reduces the flushing.

When I was about eleven years old my friend got me to take one of his mom's megadoses of Niacin. I broke out in a nasty, itchy rash and iirc it also made me sweaty and clammy. I've never touched the stuff (or most vitamins) again. Is there any long term health concern? Could this be why I am so sarcastic and bad around stupid people?

[Skammer]

I take 2000mg of Niacin a day, and sometimes the itchiness/flushing is unbearable. I take it before bedtime, and the itchiness is usually the worst in the morning after I get out of the shower. But, those itching/flushing episodes aside, it makes my skin just generally itchy all the time (especially my feet and my scalp).

Some things that help mitigate the flushing episodes for me are: taking an aspirin 30-60 minutes before the niacin (recommended by my dr as by Quadop; and not taking the niacin/going to bed on an empty stomach. If I remember to have a piece of fruit, crackers and cheese or half a PB sandwich before bed, I will thank myself in the morning.

The constant, general itchiness has diminished over time, but I've also just gotten used to it.

[Qadgop the Mercotan]

Originally Posted by ShibbOleth

Is there any long term health concern? Could this be why I am so sarcastic and bad around stupid people?

No and no.

[DrDeth]

There are special Niacin formulations desgigned to stop the "Niacin Flush".

[ltfire]

Here's just one ad from Google. There are many brands.

http://www.vitaminlab.com/product.cf...O-FLUSH-NIACIN

[KarlGauss]

Yes, there are a number of propietary forms of 'long-acting' niacin which diminish the tendency to flush (which, by the way, is NOT mediated via histamine but rather through prostaglandins. Those of you familiar with biochemistry will now understand why aspirin is used to minimize the flushing tendency).

Anyway, the long-acting preparations are not just fairly expensive but, more importantly, have been associated with severe, fulminant liver disease (as well as less severe forms, too). As far as I know, that is always the case - it is not limited to a particular brand. All long acting niacin preparations are more likely to cause liver damage than standard, short-acting niacin. So, it's a trade off: less flushing and more chance of hepatitis with the long-acting form OR more flushing and less chance of hepatitis with the standard form.