Pfizer’s cover-up on antihypertensive drugs

Recently the Swedish Television (November 11th) as well as the PBS television network (November 13th, as a follow-up on their Frontline program ”Dangerous Prescription”) reported about the ALLHAT project, a comparative study of antihypertensive drugs, led by professor Curt Furberg of Wake Forest University School of Medicine in North Carolina.

The ALLHAT study (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) found that old-fashioned diuretica such as chlorthalidone, was at least as good for lowering high blood pressure as alpha-blockers such as doxazosin. There is also a link to a possible increased risk of congestive heart failure, heart attack and stroke with doxazosin – probably not as much a side-effect as a matter of lack of effect on these conditions.

The ALLHAT study was presented in an article in JAMA almost a year ago: The ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group, ”Major Outcomes in High-Risk Hypertensive Patients Randomized to Angiotensin-Converting Enzyme Inhibitor or Calcium Channel Blocker vs Diuretic”, JAMA, December 18, 2002—Vol 288, No. 23 2981-2997. It is available as a PDF file at the ALLHAT site or here. The authors conclude:

Thiazide-type diuretics are superior in preventing 1 or more major forms of CVD [cardio-vascular disease] and are less expensive. They should be preferred for first-step antihypertensive therapy.

The ALLHAT study was terminated prematurely since the research team did not want to jeopardize the participating patients’ health by giving them a drug that the team suspected did not provide the best remedy. The drug company Pfizer, who manufactures a doxazosin drug called Cardura (in Sweden the trade mark is Alfadil), started a counter campaign. But the company had also to face a lawsuit from a patient who had taken Cardura. In this trial a lot of internal Pfizer documents were disclosed to the public. Here we can read, among other things, the survey that a PR firm executed in order to check whether doctors were aware of the critique against Cardura or not. Thus they would be able to customize their ”damage control” letters to physicians of different medical specialties. See this PDF at the FDA website, pages 104-106.

Björn Dahlöf, a Swedish scientist and consultant to the drug industry, claimed in the Swedish TV program ”Uppdrag granskning” that the JAMA article had never been peer-reviewed, something he later admitted was not true. There has obviously been attempts not only to discredit Furberg, but also to stop doctors from listening to his lectures. At a conference in Anaheim, California, in the spring 2000, the drug company organized a sight seeing tour for some of the doctors at precisely the time when Furberg was about to deliver his lecture. In the TV program Furberg says that this was hardly a coincidence. And it was not. The confidential Pfizer documents from the trial, now at display at the FDA web site, prove that this in fact was a deliberate measure. Karole M. Oleksey, of the Cardura marketing team, with special responsibility for Spain and Italy, writes in an e-mail on March 16, 2000 (page 109 in the PDF):

I saw Loris and Alessandro here at the ACC this morning at the ALLHAT presentation. I am sure they will fill you in on the presentation of the results. The good news is that they were quite brilliant in sending their key physicians to sightsee rather than hear Curt Furberg slam Pfizer once again!

This is not surprising since drug companies have acted in similar ways before at conferences, for instance by marking journalists man-to-man to keep them from talking to certain scientists with unwanted views. See for instance my article ”Consensus and canaries” footnote no 69.

A mini-interview (in English) with Curt Furberg about his and the study group’s findings is available at the ESI Special Topics Web site.

The PBS writes about Furberg as a follow-up on the program ”Dangerous Prescription”:

”If you eliminated all the ACE inhibitors and calcium antagonists [calcium channel blockers] for the first-line treatment of hypertension,” says Furberg, and if patients were put on diuretics, ”we would avert maybe 60,000 events per year – 60,000 heart failures or strokes. These are devastating complications. So, if you want to know what has happened over the past five years, we’ll you can multiply by five. So we’re talking about a large number of people who unnecessarily have suffered these events because we didn’t have the knowledge we have today.” (See Andrew Liebman’s ”Producer’s notebook”)

For Swedish readers there is an article on Furberg at the Svenska Dagbladet web site, published November 16th, titled ”Läkemedelsindustrins fiende nummer ett” (”The drug industry’s enemy number one”). On the web is also a written article from the Swedish television accompanying their program ”Uppdrag granskning” (November 11th), titled ”Dolda fakta om blodtrycksmedicin” (”Hidden facts about antihypertensive drugs”).

Pingad på Intressant.