It's Enough To Give You High Blood Pressure

Is it possible that a federal agency can, in the name of improving public health, make a decision that will not only make things worse, but cost consumers billions of dollars in the process? Not only is it possible, you can watch it happen next week by tuning into a Food and Drug Administration advisory committee meeting that will consider how drug companies label blood pressure control pills.

First some background. Fighting high blood pressure is big business. Over 65 million Americans suffer from hypertension. Well over half of them are already on medication, most on more than one drug. Pricetag? Well over $15 billion. And with the 77 million Baby Boomers heading into their high blood pressure years, the sky is the limit.

There are at least seven classes and more than 60 drugs to fight this symptom (high blood pressure by itself is not a disease; it causes heart attacks, strokes, congestive heart failure and many diseases associated with cardiovascular ill-health, such as kidney failure). Some blood pressure reducers like diuretics – the so-called water pills – have been around since the 1950s and have long been generic. Guess what? There aren’t any perky drugs salespersons out there pushing diuretics.

On the other hand, antihypertensive classes like calcium channel blockers (Pfizer’s Norvasc is the best-selling antihypertensive in the world) and angiotensin II receptor blockers (so-called ARBs) have been around for about a decade and are still on patent. There’s even a new class – the plasma renin inhibitor -- in the pipeline, promising its promoter (Novartis) many years of patented profits from treating high blood pressure.

It would be easy and tempting to say (especially for a cost-conscious consumer like me) that all these drugs are the same. As long as they lower blood pressure, what’s the difference? Go with a generic. But in fact, a lot of government-funded research in recent years has uncovered crucial differences between these various classes. While they are all fairly effective in lowering deaths from heart attacks and reducing overall mortality, some are more effective than others in reducing the number of strokes. Some are worse than others in slowing the arrival of congestive heart failure. And some don’t work as well in African-Americans.

There’s a lot of scientific speculation about the reasons for these differences between drugs. But there’s not much explanation beyond the simple fact that the differences are statistically significant when tested in controlled clinical trials.

Given those differences, the 11 physicians on a review panel established by the National Institutes of Health made the unambiguous determination in December 2003 that “diuretics have been virtually unsurpassed in preventing the cardiovascular complications of hypertension.” This 7th Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure concluded “diuretics should be used in drug treatment for most patients with uncomplicated hypertension, either alone or combined with drugs from other classes.”

When it came to patients who already suffer from the various complications of untreated high blood pressure, the guidelines turned quite specific. Calcium channel blockers (can you say Norvasc?) are singularly less effective in preventing congestive heart failure. After a heart attack, you’d probably want to start a patient on a beta-blocker or a ACE (angiotensin converting enzyme) inhibitor. Suffer from recurrent strokes? Diuretics and ACE inhibitors (both classes almost entirely generic) are best. How about diabetics? They all work about the same.

My point is not to turn you into a hypertension expert, but simply to call attention to some of the complexities that underscore why the FDA’s draft “Guidance for Industry for Labeling for Outcome Claims for Drugs to Treat Hypertension,” which will be discussed next week by the Cardiovascular and Renal Drugs Advisory Committee, is such a curious document. It isn’t so much that it is wrong. It’s what it leaves out and, more importantly, what it puts in that makes one wonder if the agency has sold its soul to the drug industry.

In its key paragraph, the draft essentially says that drug manufacturers can claim that all drugs work about the same. “Numerous single studies and pooled analyses have tested whether drugs given to achieve the same blood pressure goals have the same clinical benefits. To date, such studies have not distinguished the effects of different treatments on the (emphasis added) major hypertension-related outcomes (strokes, myocardial infarction, and cardiovascular mortality).” Note what they left out on those “major” outcomes: congestive heart failure. One can almost hear the officials at Pfizer saying thanks.

Next, the guidelines state that other properties of antihypertensive drugs (e.g., effects on heart failure or diabetic nephropathy) will often be a reasonable basis for deciding which drugs to use or to use first.” While in theory this could be a positive thing if applied to agents that are less effective in reducing heart failure, it opens the door for labeling abuse.

The medical literature is filled with industry-funded studies that measure the antihypertensive effects of specific agents on patients that have other problems like kidney disease or peripheral arterial disease. These trials, which are sometimes referred to as “seeding trials,” are a way to highlight one drug within this crowded field by getting articles about it published in specialty journals. If the FDA allows these trials to be included on labels, it allows drug detailers to mention that “benefit” to physicians. In essence, it puts the FDA imprimatur on some of the most abusive sales tactics in today’s pharmaceutical marketplace.

Some might argue this is only guidance. Companies don’t have to follow it. Physicians and patients don’t read labels anyway. All true.

But the savvy marketing arms of the major drug companies know what’s at stake. Combine a failure to distinguish between drugs with the right to put the misleading claims of seeding trials on labels and what you’ve given them is a blank check to suggest their pricey patented drugs are superior to generic diuretics, even though the government guidelines say just the opposite. The net effect of this Guidance could be a huge setback for public health and the public purse.

Posted by gooznews at April 21, 2006 05:14 PM