Hazard Seen in Blood Pressure Drugs : Health: Patients taking calcium channel blockers may be increasing their risk of heart attacks by 60%, researchers say.
Six million Americans who are taking a class of drugs to lower blood pressure may instead be increasing their risk of heart attacks by 60%, researchers reported Friday.
The drugs, called calcium channel blockers, are nifedipine, diltiazem and verapamil. They are sold under various brand names, including Adalat, Calan, Cardizem, Dilacor, Isoptin, Procardia and Verelan.
National guidelines recommend the use of beta blockers and diuretics to lower high blood pressure.
Calcium channel blockers have been widely used to treat high blood pressure, but in recent years studies have shown they do not work very well and are not considered the best treatment, said Dr. Paul Ridker, a cardiologist and epidemiologist at the Brigham and Women’s Hospital in Boston.
However, many American cardiologists are still prescribing them for that purpose, said study author Dr. Bruce Psaty, an epidemiologist at the University of Washington in Seattle.
Previous studies have suggested that calcium channel blockers can be dangerous when given to patients immediately after a heart attack, or when they are given some time later to prevent a second heart attack.
This is the first suggestion that they are dangerous in the large group of outwardly healthy people who are trying to prevent heart attacks by lowering their blood pressure, Psaty said. Researchers said they did not know why the drugs may increase the risk of a heart attack.
About 50 million Americans suffer from high blood pressure, greatly increasing their chances of a heart attack.
Half of those are being treated, and about 25% of the patients being treated are getting calcium channel blockers, Psaty said. That amounts to about 6 million Americans.
Ridker, who was not involved in the study, said doctors continue to use calcium channel blockers in part because drug companies have “marketed them beyond what the data shows.”
Another reason may be that many cardiologists are not familiar with the most recent research data on the drugs’ effectiveness.
Psaty studied 623 people who had had heart attacks and a control group of 2,032 who had not. When he determined the drugs they had been taking, he found that those on calcium channel blockers had a heart disease risk 60% higher than those taking beta blockers or diuretics. The study was funded by the National Institutes of Health.
