Friday, July 6, 2012

Pressure Rising But Not As Fast As Costs

Trying to learn all I can about evaluating clinical studies, I recently completed a book aptly titled, "Evaluating Clinical Research, All That Glitters Is Not Gold," by Bengt Furberg and Curt Furberg.  

Suffice it to say that I learned a lot from this book about what to look for in a study to determine if it offers valuable and practical data. One of the examples repeatedly used in the book to show how data can be manipulated refers to studies of blood pressure medications. The book reveals numerous examples of how many of the new hypertensives have shown little benefit over the long used, inexpensive diuretics as a first line therapy for high blood pressure. Diuretics reduce your body's fluid volume, which often reduces blood pressure. I didn't think much about these examples because I haven't look at the full body of research on blood pressure control medication so I read about them with a passing fancy.

So when I came across an interesting article yesterday titled, "Rethink Pills for Hypertension," on a Canadian website, it caught my attention.

Here's the article:

The gist of the article is that while new medications have substantially raised the cost of treating hypertension, hypertension continues to increase across the Canadian population. Of course, there can be many reasons for more hypertension including increasing heart disease, diabetes, obesity, etc.

Nevertheless, the article reports, "In a study published in the Canadian Medical Association Journal, the authors documented that the cost for these medications rose to $5.3 billion in 2006 from $1.7 billion in 1996. The cost per 100,000 population rose to $17.5 million from $5.8 million during that 10-year period. The authors observed no plateau in spending and concluded that the rapid escalation in costs threatens the sustainability of public drug insurance programs."
So what's the problem? According to the article, "Of the 88 new patented drugs used during the study period, only 20 per cent offered a new active substance, let alone an actual clinical improvement...The first issue is that cheaper diuretics actually are superior to anti-hypertensive medications in treating high blood pressure. "

The article also shared the following study results, some of which were also discussed in my book; please note that I have not independently verified these studies.
"The Cochrane Collaboration performed a meta-analysis and found that no other drug class improved health outcomes better than diuretics. An interesting part of this analysis was that low doses of diuretics prevented coronary heart disease by 28 per cent and mortality by 11 per cent, while higher doses of diuretics did not. This same review also found that more expensive beta blockers and calcium channel blockers were not effective in reducing coronary heart disease and mortality. There were 14.8 million prescriptions filled in 2006 alone for beta blockers. The authors of the review concluded that low dose diuretics should be the first choice of drugs for patients with high blood pressure, and that it is fortunate that diuretics also are very inexpensive."

Furthermore, the article reports that "The Cochrane Collaboration published four meta-analyses on the effectiveness of anti hypertensives in reducing blood pressure. ACE inhibitors, alpha blockers, ARBs and beta blockers all reduce systolic blood pressure by a range of seven to eight points, and diastolic blood pressure by a range of five to six points. However, in these systematic literature reviews, the average blood pressure prior to treatment was 157/101 mmHg. As such, these medications reduced blood pressure to only 149/96 - well above the target of 120/80." That's not much of an improvement and leaves blood pressure too high for comfort.

The conclusions of the article are essentially that instead of using new (actually, not always new chemicals) expensive, patented blood pressure lowering drugs, doctors as a first-line therapy should stick with the tried and true, and very inexpensive, diuretics because they work as well if not better.

According to Mark Lenstra, the author of the article, if the new drugs showed limited benefit in a carefully controlled study where complianace is high and you expect the best results, what can you expect in the real world where there is less compliance. I don't share that concern because I believe that a drug should be evaluated based on when it is actually taken and not on what happens when someone doesn't take it.

Nevertheless, I have to agree with Mark's original premise that it may be time to reconsider leapfrogging over diuretics as a first line therapy to more expensive, but no more effective, patented drugs. Combining the data from the book I just finished and these studies, that would seem to be the logical conclusion.

Although diuretics are by no means perfect, I think I will give them a more careful consideration moving forward in initially treating a patient's high blood pressure.


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