Blood Pressure Medication Is Not Administered To Best Protect Against Heart Attack, StrokeMay 17, 2002 | INTERNET WIRE
A majority of physicians tell patients to take their antihypertensive medication at a time of day that may not adequately protect them against potentially dangerous surges in blood pressure. According to a new survey by The Gallup Organization, little more than half of primary care physicians (PCPs) consider the body's natural rhythms when prescribing treatments for high blood pressure, although more than 90 percent recognize these factors may put patients at a higher risk for heart attack and stroke during certain periods of the day.
"The findings underscore a critical disparity between what physicians know about fluctuations in natural body rhythms, or circadian rhythms, and how they use that knowledge to protect patients against potentially serious adverse events," said Janice Douglas, MD, chief of the Division of Hypertension, Department of Medicine, Case Western Reserve University School of Medicine in Cleveland, Ohio. "Clearly, the medical community must address how to best translate new understandings about circadian risks into meaningful adjustments in prescribing practices."
"A.M. Surge" Rarely Addressed
A growing body of evidence illustrates that the early-morning rise in blood pressure - or "a.m. surge" - experienced by most people may increase the risk of heart attack and stroke, particularly in individuals who suffer from hypertension. In fact, researchers have identified a 49 percent higher risk of stroke, a 40 percent higher risk of heart attack, and a 29 percent higher risk of cardiac death in the hours between 6 a.m. and noon.(1)
The Gallup survey demonstrated that PCPs were highly aware of these risks. Slightly more than 80 percent of PCPs surveyed acknowledged that circadian rhythms put patients at the greatest risk for heart attack and stroke "immediately upon awakening" or "in the morning." Yet, of the 88 percent who said they advise patients to take their antihypertensive medication at a certain time of day, more than two-thirds (68 percent) recommend "in the morning" or "upon awakening" as the optimal time. That dosing schedule does little to shield patients from morning circadian risks because blood pressure medication can take hours to reach peak concentrations.
"The survey shows a concerning trend - that the overwhelming majority of hypertensive patients are taking their medication in a way that fails to protect them when they are most vulnerable," said Dr. Douglas. "Nighttime dosing should be strongly considered because it allows blood pressure medication to reach peak concentrations as morning circadian variations begin to appear. But the survey showed only 21 percent of physicians are recommending evening or bedtime administration."
Patients Confirm Treatment Gaps
A separate arm of the survey, which studied 600 randomly selected antihypertensive patients ages 50 and over, confirmed, and in some instances compounded, the findings of the physician poll. For example, only 38 percent of patients reported that their doctors recommended a particular time of day to take their blood pressure medication. Of those, 77 percent said they were directed to take their antihypertensive "upon awakening" or "in the morning." Only 17 percent were instructed to take their medication "at night" or "at bedtime." Overall, 80 percent of patients took their blood pressure medicine once per day, and 83 percent of that group took their only dose "upon awakening" or "in the morning."
"Traditional antihypertensive medications are not designed - and are clearly not being administered - in a way that adequately addresses increased morning risks," noted Stephen Glasser, MD, professor of epidemiology, University of Minnesota, School of Public Health. "To maximize the many advantages of once-daily dosing, physicians must ensure that peak concentrations are in effect when patients need them most. Given the prevalence of morning administration, most patients enter the 'a.m. surge' with the lowest concentrations of the day."
Toward More Timely Treatment
Chronotherapy, a relatively new approach to drug design and administration, may provide additional help to people with hypertension and other disorders. Chronotherapy coordinates medical treatment with the body's circadian rhythms, and ensures the timing and amount of drug delivered optimizes the desired effects while minimizing adverse events.(2)
"The ability to deliver the highest amount of a drug during the greatest time of need, in this case between the hours of 6 a.m. and noon, addresses the circadian surge in blood pressure and offers patients the best possible protection from adverse cardiovascular events," said Dr. Glasser.
Accordingly, the poll found that 97 percent of PCPs surveyed said it would be beneficial to have an antihypertensive medication available that reached peak concentrations during the time of day when patients need it the most. And more than half (53 percent) of PCPs familiar with circadian rhythms said it would be "very beneficial." In addition, 81 percent of patients ages 50 to 64 and 59 percent of patients ages 65 and over said it would be beneficial.