Saturday, October 09, 2004
In 2001, I was part of a team from the Cleveland Clinic that published a paper demonstrating the significant heart attack risk of Vioxx. Our research, published in The Journal of the American Medical Association, found that compared to naproxen, a commonly used over-the-counter anti-inflammatory drug with similar benefits, Vioxx has a five times greater heart attack risk. In response, Merck claimed that early conclusions about the risk were flawed, and attributed the comparatively high heart attack rates to an unproven protective effect of naproxen. Our study was followed by several others demonstrating Vioxx's dangers. Each time Merck had a similar reply: the study was "flawed."
No need for the scare quotes. Dr. Topol's study was flawed. It compared Vioxx, which doesn't inhibit platelets, with Naprosyn, which does.
(Platelets play a critical role in blood clotting.) To further confuse things, his study also found no difference in cardiovascular events between Celebrex, a drug similar to Vioxx, and other drugs similar to Naprosyn. To top things off, the number of cardiovascular events were too small to make much of a conclusive statement. Even his concluding statement was not "these drugs are dangerous," but that these drugs need to be studied a little more.
Merck finally had to acknowledge the truth, but only by accident. The company undertook a large, randomized trial of 2,600 patients with colon polyps in hopes of proving that Vioxx could help their condition. In the process, though, Merck discovered that 3.5 percent of patients taking Vioxx suffered heart attacks or strokes as against 1.9 percent taking a placebo. Merck at last did the right thing by voluntarily and abruptly taking Vioxx off the market.
There are two important issues to consider here. First, the risk of heart attack or stroke found in the Merck study, at 15 cases per 1,000 patients, may be greatly underestimated. Merck's trial did not include anyone with known heart disease - patients who might be expected to have the highest risk.
I think that would be 14 cases per 1,000, but why nitpick? (Bad math on my part, it is 15 -ed.) What about the risk of aspirin, which I'm sure that Dr. Topol recommends for all, of his patients? 3 out of 1,000 people who use aspirin daily to prevent strokes and heart attacks will either either bleed from their gut or bleed into their brain. And that's just healthy people. The risk goes up for those who have had gastroinestinal bleeding, or who have uncontrolled hypertension, or who are very elderly - the very people who are the most likely to have cardiovascular disease and thus be placed on aspirin. Clearly, Dr. Topol, and most physicians, believe the benefits of aspirin therapy outweigh these risks. That's why so many of us insist that everyone with heart disease be on aspirin, regardless of their other risks. Cardiologists even push this further. Many of them insist on aspirin therapy for people who have already had hemorrhagic strokes or GI bleeds. They only care about the heart and its risks.
Which brings us to the real problem with Dr. Topol's angry missive. He only sees the world and his patients through cardiovascular glasses. Maybe an elderly patient with arthritis would prefer to take the 1 to 2 percent risk of a heart attack to get rid of his joint pain. Only the patient knows how much the relief is worth. Not Dr. Topol. Not me. But Dr. Topol wants to take these pain relief options away from millions of arthritis sufferers:
And the problem may extend beyond Vioxx and its users. While it's true that when compared to the other Cox-2 inhibitors, Vioxx has repeatedly carried a far greater risk of heart attack and stroke, none of the manufacturers of Vioxx's class of drugs, called Cox-2 inhibitor agents, have studied patients who already have heart disease. The number of patients who may have sustained heart attack or stroke as a result of using these drugs could be tens of thousands. It would be premature to conclude that the other drugs still on the market, like Celebrex and Bextra, do or do not carry some risk of heart attack until sufficient testing is done.
While we remain in this zone of uncertainty, people with arthritis should remember that conventional over-the-counter agents like naproxen (as in Aleve) or ibuprofen (as in Advil) work extremely well, are much cheaper than the Cox-2 agents, and are not known to have any risk of heart attacks. In addition, one of the most-cited benefits of the Cox-2 agents - that they are less likely to cause stomach ulcers than over-the-counter drugs - may ben grossly exaggerated.
My experience has been that fewer patients complain about stomach upset with Cox-2 agents than with traditional NSAIDs. I've also never had to admit someone with a GI bleed caused by them, despite what the research says. I can't say the same thing for the NSAID class. I've admitted many. And, it ignores the fact that everyone responds differently to each of these arthritis drugs. I have many patients who have only turned to Cox-2 drugs when the NSAIDs failed to relieve their pain - and they've been successful. Things aren't supposed to work this way, according to textbooks and experts, but they do.
...As the Vioxx debacle shows, we have a long way to go in this country to get on track with prescription medications. Most important, we need a stronger regulatory agency to compel pharmaceutical companies to do the proper studies and force these companies to stop direct-to-consumer advertising unless a drug has major benefits for patients and negligible increased risk of heart attacks and strokes.
Our two most common deadly diseases should not be caused by a drug.
I'm not terribly fond of direct to consumer advertising for prescription drugs, either, but that's a rant for another day. But it's a dreadful exaggeration to say that these drugs "cause" heart attacks and strokes when the difference between the difference in strokes and heart attacks between Vioxx and placebo was only a little over 1%. Clearly, something else causes them - aging being the biggest culprit.
As one of my patients told me when I recommended she go on cholesterol lowering medication - "No thanks. I'd rather die young of a heart attack than live long enough to get cancer." I'm sure there are more than a few elderly people who would be willing to take the very small risk of a heart attack or stroke if it meant walking without pain. But if Dr. Topol and his ilk have their way, they'll never be given that chance.
UPDATE: Corrected my bad math error. Good thing I live in the age of calculators.
posted by Sydney on 10/09/2004 02:16:00 PM 0 comments