>From July 1999 edition of the National Post (Canada)
Cheap Pill at Heart of B.C. Research
By Margaret Munro
Pills for high blood pressure that cost less than one cent a day appear to be
as good or better at preventing strokes and heart attacks than costly pills
aggressively marketed by drug companies, says a report in this week's Canadian
Medical Association Journal.
The report by a team of B.C. researchers takes aim at the most widely
prescribed pills in the world. Physicians should consider treating their
patients with low-dose thiazide, which has been on the market for decades, says
Dr. James Wright and his team of drug assessors at the University of B.C.
"Why would you want to spend 100 times more for drugs that haven't been shown
to be any better," Dr. Wright said in an interview, adding that people taking
expensive anti-hypertensive drugs might want to discuss their prescriptions with
their doctors.
In their report, the researchers present the results of the most comprehensive
review yet published of the many drugs used to treat hypertension. They examined
23 trials of drugs used as first-line therapy for uncomplicated hypertension.
The trials involved 50,853 people.
No other treatment, they report, has proved to be more effective in preventing
strokes and heart attacks than standard and inexpensive low-dose thiazide
therapy.
"Low-dose thiazide therapy can be prescribed as the first-line treatment of
hypertension with confidence that the risk of death, coronary artery disease and
stroke will be reduced," they conclude.
"The same cannot be said for high-dose thiazide therapy, beta-blockers,
calcium-channel blockers or ACE inhibitors."
Drugs to treat hypertension are currently the most commonly prescribed pills
in the world, with worldwide sales in the "billions" of dollars, says Wright. He
estimates that two to three million Canadians are being treated for high blood
pressure.
Currently, he says, only about a third of them are being prescribed thiazides.
The number, he says should be "considerably higher, maybe 75%.
"The point is, if you want your patient to be on the drugs with the best
evidence for effectiveness, this is the class you want, Wright says of low-dose
thiazides.
Thiazides, which are sometimes called water pills, are sold under the chemical
names hydrochlorothiazide and chlorthalidone. They have been on the market for
more than 40 years. A daily dose costs .3 to .6 cents a day, depending on the
dose, compared to up to $2.50 a day for the most expensive of the newer
anti-hypertensive drugs.
Thiazides are "clearly the drug of first choice" when treating uncomplicated
hypertension, says Wright, who is director of the high blood pressure clinic at
Vancouver Hospital. He is also managing director of a team at the University of
B.C. that assesses the effectiveness of drugs for the provincial government.
Many doctors do not bother trying the inexpensive and effective thiazides that
have been around for decades, says Wright.
"We've been brainwashed into thinking new is better, but it is often not the
case," Wright said."Older drugs are often the best."
One of the problems, says Wright, is that drug companies heavily market new
drugs to doctors.
But there is little promotion of thiazides, which are no longer protected by
patents and are therefore less lucrative for the companies. As a result, he
says, use of the thiazides that have the best evidence of effectiveness is
decreasing while use of more costly and unproven ones is climbing.
The Canadian Medical Association Journal report looked at studies of
anti-hypertensive drugs that had been completed by the end of 1997. Wright says
there have been no studies since that would alter his team's conclusions.