People with high blood pressure can have widely varying mental and physical problems, depending on what type of medication they take, according to a scientific study.
The study, to be published in today's New England Journal of Medicine, "will have a profound impact on the way that doctors practice," according to Dr. James Schoenberger, a past president of the American Heart Assn.
"Patients will realize that they shouldn't put up with subtle side effects . . . and doctors will learn that they should listen (to patients) more," he said in a telephone interview.
While such conclusions might appear self-evident, an estimated 20% of the 60 million Americans who suffer from hypertension do not take their medicine because of side effects.
Those studied had differing complaints about such things as fatigue, lethargy, sexual disorders, headaches, neck pressure, insomnia and nightmares, depending on which of three drugs they took.
When medically possible, doctors should begin choosing between the three medications to find the one that causes the fewest problems for patients, Schoenberger said.
Negative side effects have been major obstacles to convincing those with high blood pressure that they should continue taking medication that sometimes makes them feel worse.
That problem is compounded by the fact that high blood pressure itself commonly produces no unpleasant sensations. But left uncontrolled, hypertension significantly increases an individual's chances of having a stroke or other cardiovascular illness.
The principal researcher for the study was Sydney H. Croog, a behavioral scientist at the University of Connecticut. Research was carried out at 30 medical centers around the nation, including the Veterans Administration Hospital at the University of California, San Diego, Medical School.
The study was based on the experiences over a six-month period of 626 white males, aged 21 to 65, with mild or moderate hypertension, who were taking one of three anti-hypertension drugs: captopril, methyldopa or propranolol.
Even though only white males with jobs were included in the study, the researchers said that the conclusions about mental and physical problems could be applied to other groups, such as women, blacks, the unemployed and the elderly.
Dr. Daniel T. O'Connor Jr., head of the hypertension clinic at the UC San Diego Veterans Hospital, said that only employed white males were included in order to reduce statistical problems in trying to show differences between drugs.
Homogeneous Group Sought
"The more homogenous the group, the easier it is statistically to show differences," O'Connor said. "Strictly speaking, our results are limited to white males, but common sense tells us that the results can be applicable to females, the unemployed, and various ethnic groups. Often in medicine you have to use your best judgment."
Although all three drugs reduced blood pressure, 83 patients did not finish the study because of adverse drug reactions, according to the report.
Those studied reported physical problems and underwent a variety of tests to determine mental problems.
Patients taking captopril had a 40% to 60% lower rate of withdrawal from the study because of side effects. According to the report, the overall quality of life for patients on captopril was significantly better than for those taking the other two drugs. Improvements were noted in work performance and in cognitive functioning.
In contrast, the patients taking methyldopa only showed improvement in cognitive functioning, and by the end of the study, they had become more depressed and began to have sexual and work-related problems.
The group taking propranolol showed improvements in cognitive functioning and participation in social activities, but sexual and physical problems also increased.
In addition to the anti-hypertension drug, about a third of the patients received another drug, a diuretic that causes the body to lose fluids. In all three treatment groups, the addition of the diuretic caused negative side effects. But, the report said, even with the addition of a diuretic, patients taking captopril had fewer problems than those taking the other two medications.
60 Million Victims
According to Schoenberger, 60 million Americans have diastolic blood pressure above 90. Mild hypertension, he said, is defined as diastolic pressure between 90 and 104.
"Many physicians become so involved with the patient's blood pressure problem they they tend to be less aware of the quality-of-life aspects of the therapy," said Sol Levine, a Boston University behavioral scientist who took part in the study.
Yet, Levine continued, it has been well documented by numerous studies that people who experience a poor quality of life because of the medication are apt to stop using the medication.
UC San Diego's O'Connor said that physicians should now be more amenable to switching drugs if a patient complains about side effects, although he cautioned that captopril can sometimes bring undesired effects, such as rashes. In addition, captopril is more expensive than other drugs because it is still patented and not available generically, he said.
O'Connor said that Squibb Pharmaceutical, which holds the patent on captopril, paid for the study.
"But even though some people might wonder that Squibb paid for the study and its drug won . . . the study was a double-blind study (meaning that neither doctors nor patients knew which drug they were using) and the codes to the drugs were not broken until the data had been compiled by researchers."
Staff writer David Smollar contributed to this article from San Diego.