Fri, 2 Jan 2004 19:30:53 GMT in article
<[email hidden]> "Patrick Blanchard M.D."
[email protected] said:(Sonny) said:Out of curiosity I had to find out why all this cardio stuff was showing up on alt.tinnitus. Yow
! This place is as trippy as ast is/was/will be ? Anyway, since I'm here, I take Cardizem, any
thoughts on that med ?
Sonny
Calcium channel blockers like Cardizem (diltiazem) and Isoptin (verapamil) are not my first choice
for treatment of hypertension unless there is a cardiac rhythm disturbance like atrial fibrillation
associated with the hypertension.
There are better choices, and often much less expensive that address the main concern associated
with hypertension, namely atherosclerosis and the treatment of it.
That's also my observation. However, many doctors still against recommendations prescribe new,
considerably more expensive antihypertensive medications, perhaps because physicians may have been
influenced by drug company advertising. There is new study about this topic:
Ubel PA, Jepson C, Asch DA. Misperceptions About beta-Blockers and Diuretics. J Gen Intern Med. 2003
Dec;18(12):977-83. PMID: 14687255 [PubMed - in process] <URL:http://www.ncbi.nlm.nih.gov/entrez/que-
ry.fcgi?cmd=Retrieve&db=PubMed&list_uids=14687255&dopt=Abstract>
"... CONCLUSIONS: Despite numerous clinical trials showing no difference in the effectiveness or
side-effect profiles of these 4 classes of drugs, most physicians believed that diuretics were
less effective and beta-blockers were less tolerated than other medications. Moreover, their
prescription practices were associated with their provision of free samples provided by
pharmaceutical representatives, even after adjusting for other demographic characteristics.
Efforts to increase physicians' prescribing of beta-blockers and diuretics may need to be
directed at overcoming misunderstandings about the effectiveness and tolerability of these
medicines.
Comments in
Doctors More Likely to Prescribe Pricey New Blood Pressure Drugs Despite Standards
<URL:http://www.newswise.com/articles/view/502414/>
"Even though research has shown inexpensive treatments for high blood pressure are just as
effective as pricey new drugs, doctors perceive the new drugs as more effective and think they
carry fewer side effects, according to a new study by a University of Michigan Health System
physician.
[...]
“These new, more expensive medications are being more heavily promoted by the drug companies,
and one way or another that information influences how people perceive the drug’s
effectiveness,” says study author Peter A. Ubel, M.D., associate professor of internal medicine
at the U-M Medical School and director of the U-M Health System’s Program for Improving Health
Care Decisions.
[...]
“The industry influence is pervasive,” says Ubel, who is also a research investigator at the
Ann Arbor Veterans Administration Health Center. “I think a lot of physicians do rely on sales
representatives to tell them about the latest medications out there. How else do you find this
out? It is very hard to keep up on the medical literature. Doctors feel it’s an educational
visit, but the sales reps hand out samples.”"
This matter doesn't seem to have changed much in five years. In September 1998 The Lancet
published the study
Malcolm Maclure, Colin Dormuth, Terryn Naumann, James McCormack, Robert Rangno, Carl Whiteside,
James M Wright. Influences of educational interventions and adverse news about calcium-channel
blockers on first-line prescribing of antihypertensive drugs to elderly people in British Columbia.
The Lancet Volume 352, Number 9132, 19 September 1998, pp. 943-948.
<URL:http://www.thelancet.com/journal/vol352/iss9132/full/llan.352.9132.original_research.6005.1>
from which one can conclude that new widely reported scientific observations only very slowly affect
the doctor's prescribing behavior. The above study has been commented in the article
Prescribing habits often slow to change
dailynews.yahoo.comstory.htmlOpen ↗
thriveonline.com740.htmlOpen ↗
The links are now obsolete, but I happen to have saved the following citation:
"Many Canadian doctors continued to prescribe certain drugs for patients with high blood
pressure even after an avalanche of media coverage on the possible health risks of these drugs,
and against recommendations published in professional guidelines, according to a new study.
The study findings ``are consistent with other research showing that physicians are cautious
about changing their prescribing practices,'' the research team writes this week in The Lancet.
Dr. James Wright of the University of British Columbia in Vancouver and colleagues looked at
over 4,400 physicians in British Columbia who prescribed a diuretic, a beta-blocker, an angiotensin-
converting enzyme (ACE) inhibitor drug or a calcium channel blocker for the first time for a
total of 36,507 hypertensive patients between 1993 and 1996.
The researchers report that about 22% of these patients were prescribed calcium channel blockers
as first-line therapy in 1994 although professional guidelines suggested that beta blockers or
diuretics were more appropriate as a first choice.
And prescribing practices did not change in early 1995 after a study reported that patients
taking some calcium channel blockers might be at higher risk of heart attack than those taking
other drugs.
But the team did find that small shifts in prescribing in July 1995 and in early 1996, after the
release of more reports on the risks of these drugs in some patients.
``Our main finding was that, despite many news reports, a warning letter and two issues of a
regular newsletter, physicians continued to prescribe... (calcium channel blockers) as first-
line therapy to at least 33% of patients, contrary to guidelines,'' the authors write.
``We conclude that, for new evidence to have an immediate impact on prescribing, innovative
forms of continuing medical education and new ways of warning physicians must be developed
and evaluated,'' they conclude. ``In the meantime, prescribing can be expected to improve
only gradually in response to multiple messages delivered by multiple methods, including the
lay media.''
SOURCE: The Lancet 1998;352:943-948."
More about this topic in the abstract of the study
Manolio TA, Cutler JA, Furberg CD, Psaty BM, Whelton PK, Applegate WB. Trends in pharmacologic
management of hypertension in the United States. Arch Intern Med. 1995 Apr 24;155(8):829-37.
Review. <URL:http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=771779-
1&dopt=Abstract>
A citation:
"CONCLUSIONS: Use of calcium antagonists and angiotensin-converting enzyme inhibitors in
hypertension has increased dramatically in the past 10 years. Without convincing evidence of the
advantages of these agents, it is difficult to explain the continued decline in the use of less
expensive agents, such as diuretics and beta-blockers, which are the only antihypertensive agents
proved to reduce stroke and coronary disease in hypertensive patients."
Comments in the articles
Study: Calcium Antagonists and ACE Inhibitors Overused in Hypertension
pharminfo.comccbace ovr.htmlOpen ↗ (link no longer worksi)
"Manolio et al. explored possible reasons for the shift to newer types of drugs. These included
improved efficacy in preventing cardiovascular morbidity and mortality, rising incidence of
concomitant illnesses necessitating the use of newer drugs, improved blood- pressure-lowering
effects, improved side effect profiles, lower cost, and increased marketing pressure and
attractiveness of newer drugs.
The investigation showed that changes in drug use could not be explained by any of the first
five reasons."
[...]
"The investigators concluded, "Although there may be legitimate reasons, such as coexisting
angina or congestive failure, to choose newer agents in selected patients, this does not appear
to justify their use as routine therapy in uncomplicated hypertension. No data are currently
available to demonstrate the superiority of calcium antagonists and ACE inhibitors in reducing
cardiovascular morbidity and mortality from hypertension, but there is ample evidence of their
greater cost. While health costs are under sharp attack, it seems irrational to divert
substantial resources by substituting unproven and more expensive remedies for tried and tested
drugs. Since the vast majority of hypertensive patients can be treated with relatively
inexpensive, proved agents, the trend toward increased use of costly, unproved agents in routine
management of hypertension requires careful reconsideration." "
and
Doctors Not Prescribing Recommended Drugs to Treat Hypertension
heartinfo.comhbpdrg12497.htmOpen ↗ (link no longer works)
"There are enormous cost implications of prescribing calcium channel blockers instead of
diuretics, according to the study. Since calcium channel blockers cost close to 60 times the
price of diuretics, prescribing diuretics could save hundreds of millions of dollars. Possible
reasons for doctors' prescribing habits mentioned by the authors are that not enough doctors
were informed of the treatment guidelines, and that physicians may have been influenced by drug
company advertising."
--
Matti Narkia
