Does Niacin Still Have a Role in Cardioprotection?
A number of years ago, I needed to address my rising cholesterol levels. Despite being an avid runner with a Body Mass Index well within normal limits, my total cholesterol was 250 mg/dL and my LDL (“bad cholesterol”) was 140 mg/dL – both above recommended healthy levels. Given that I have a family history of heart disease, I decided to seek medical treatment and, being a Pfizer employee, I visited my personal physician with the intent of getting a prescription for Lipitor.
Interestingly, my doctor was reluctant to do this. This was the 1990s and Lipitor was new to the market. He was not comfortable prescribing a drug that I potentially would take for the rest of my life without having seen more long term safety data. Instead, he recommended that I take long-acting niacin, which is available over-the-counter at any pharmacy.
Niacin, also known as vitamin B3, is known to raise HDL, the so-called good cholesterol, by about 25% as well as modestly lower both LDL and triglycerides. It has been used for decades to treat dyslipidemia based on results from the Coronary Drug Project (CDP). Carried out in the late 1960s, the CDP study tested niacin vs. placebo in men who’d had a previous heart attack, over a period of five years. Interestingly, niacin showed no difference from placebo in the death rate of the men in this study, but fewer patients on niacin had a non-fatal heart attack or stroke, by 26% and 24% respectively. This study is the basis of the use of niacin in cardiovascular (CV) disease.
My experience with niacin was pretty typical. There were modest reductions of both total cholesterol and LDL (~15%), but these changes weren’t maintained over time. But I also experienced the major niacin side-effect, flushing. This irritation wasn’t minor. The flushing was intense and was accompanied by itching and heat sensations. Because of this side-effect, many patients refuse to stay on this medication despite its potential benefits. After about a year, my physician took me off niacin and I started on Lipitor which was far more effective for me than niacin and which I tolerated very well.
So, why am I taking you on this stroll down memory lane? A recent study reported in The New England Journal of Medicine (NEJM.org, 11/15/11), along with an accompanying editorial, call into question the value of using niacin to treat CV disease. The AIM-HIGH trial, co-sponsored by the NIH and Abbott, looked at patients with established CV disease who were already on intensive statin therapy. The goal of this study was to see whether adding niacin therapy provided any extra benefit. The rationale for this was pretty sound. Unlike statins, niacin can significantly raise HDL and further lower LDL. Shouldn’t combining both modalities work better? Surprisingly, it didn’t. While the expected beneficial changes in terms of raising HDL did occur, adding niacin to intensive statin therapy was no different from adding a placebo in terms of preventing heart attacks, strokes or other adverse CV events.
The NEJM editorial accompanying the AIM-HIGH study results entitled, “Niacin at 56 Years of Age – Time for an Early Retirement?,” basically questions further use for niacin given the copious data with statins showing the superiority of these drugs in CV disease therapy. This is causing some intense debate amongst cardiologists, who are unwilling to give up on niacin after this one study. The defenders of niacin correctly point out that there are other long-term studies with niacin currently underway that will provide a more definitive answer to the value of niacin for treating heart disease.
Niacin is a medicine that has been used by physicians for 56 years. Physicians take comfort in the fact that it has been around for so long and it has been taken by millions of people, so they know what the side-effects are. Yet, niacin hasn’t been as intensively studied as newer classes of lipid modulating drugs. It is now being subjected to the same type of scrutiny demanded by the FDA of new drugs. I, for one, am looking forward to the completion of these studies.
As I have often written in this blog, decades of use does not ensure that a medicine is automatically safe and/or effective. Industry detractors seem to forget that pharmaceutical companies are full of people that also need medicine. I was my own case study in the effectiveness and risk-benefit profile of Lipitor versus niacin. For me, Lipitor was the answer. Whether or not that is also the case for others is a decision that a patient must make in consultation with his physician. However, one thing is for certain: only long-term, well-controlled studies can provide assurance that a medicine is both safe and effective.