Report recommends earlier treatment of hypertension
Pharmacists in unique role to assist with combination drug therapy
New clinical practice guidelines for the prevention, detection, and treatment of high blood pressure recommend earlier and more aggressive intervention for control of the disease. The guidelines also give non-physician practitioners, such as pharmacists, a better-defined opportunity to be an important part of therapy, says a pharmacist who participated in the development of the report.
In mid-May, the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health announced the release of the "Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure" (JNC 7). A practical guide, called the "JNC 7 Express," was published first on the NHLBI web site. It also was included in the May 21 issue of the Journal of the American Medical Association (JAMA) and was posted on the JAMA web site. A full-length version of the report is set to appear in the July/August issue of the journal Hypertension.
The sixth report from the JNC, a coalition of 39 major professional, public, and voluntary organizations and seven federal agencies, was published in 1997. The decision to appoint a JNC 7 committee was based on four factors, the new report says: 1) the publication of many new hypertension clinical trials and observational studies; 2) the need for a new, clear, and concise guideline that would be useful for clinicians; 3) the need to simplify the classification of blood pressure; and 4) a clear recognition that the JNC reports were not being used to their maximum benefit.
"Since 1997, much more has been learned about the risk of high blood pressure levels and the course of the disease," said NHLBI director Claude Lenfant, MD, in a statement. "Americans’ lifetime risk of developing hypertension is much greater than we’d thought."
The guidelines were prepared by an executive committee and five writing teams selected from the coordinating committee of the NHLBI’s National High Blood Pressure Education Program (NHBPEP), which represents 46 professional, voluntary, and federal organizations. The guidelines then were reviewed by 33 national hypertension experts and policy leaders and finally were approved by NHBPEP’s full membership.
The group tried to streamline and simplify the guidelines to make them as applicable to practice as possible without limiting the science and the evidence they present, says Mark J. Cziraky, PharmD, FAHA, executive vice president of Health Core in Newark, DE. Representing the American Pharmacists Association in Washington, DC, Cziraky helped write the report and also helped develop JNC 7’s tables of antihypertensive drug therapies, along with Barry L. Carter, PharmD, a professor at the University of Iowa College of Pharmacy in Iowa City and a representative of the American Society of Health-System Pharmacists in Bethesda, MD.
A new classification system
One fundamental change in the guidelines is the new approach to categorizing blood pressure levels. The old system, which some clinicians claimed is confusing, classified blood pressure levels as optimal, normal, high-normal, or hypertensive stages 1, 2, or 3. JNC 7, however, has added the classification of prehypertension, and has combined stages 2 and 3 because their treatments were essentially the same. The JNC 7 categories are: normal (less than 120/less than 80 mmHg), prehypertension (120-139/80-89 mmHg), stage 1 hypertension (140-159/90-99 mmHg), and stage 2 hypertension (at or greater than 160/at or greater than 100 mmHg).
The classifications were changed because the relationship between blood pressure and risk of cardiovascular disease (CVD) events is continuous, consistent, and independent of other risk factors, the JNC 7 Express report explains. For individuals 40-70 years of age, each increment of 20 mmHg in systolic blood pressure or 10 mmHg in diastolic blood pressure doubles the risk of CVD across the entire blood pressure range from 115/75 to 185/115 mmHg. "The new classification of prehypertension’ recognizes this relationship and signals the need for increased education of health care professionals and the public to reduce blood pressure levels and prevent the development of hypertension in the general population."
The JNC 7 report does not recommend drug therapy for prehypertension unless patients have compelling indications such as kidney disease or diabetes. The report does recommend that these patients adopt lifestyle modifications, including weight reduction, adoption of the Dietary Approaches to Stop Hypertension eating plan, dietary sodium reduction, increased physical activity, and moderation of alcohol consumption. Patients also should stop smoking for overall cardiovascular risk reduction.
The change in classification became necessary because there is more evidence that patients are at risk and that many of these patients go on to develop hypertension by definition, Cziraky says.
"Identifying patients who are in a prehypertensive category, such as 125/85, is important, as these patients can benefit from intervention through lifestyle modifications, and the onset of hypertension can be potentially delayed."
According to Cziraky, it is important for patients and clinicians to understand that a person in the prehypertension stage may see benefit from early intervention — not necessarily with medication, but at least with some discussions about lifestyle adjustments, such as salt restriction and weight reduction, he says.
Two or more drugs likely
For patients who need drug therapy to control their hypertension, the JNC 7 report recommends that thiazide-type diuretics be used as initial therapy for most patients with hypertension, either alone or in combination with one of the other classes demonstrated to be beneficial in randomized controlled outcome trials. The report also lists compelling indications that require the use of other antihypertensive drugs as initial therapy. If a drug is not tolerated or is contraindicated, then one of the other classes proven to reduce cardiovascular events should be used instead.
"Diuretics enhance the antihypertensive efficacy of multidrug regimens, can be useful in achieving blood pressure control, and are more affordable than other antihypertensive agents. Despite these findings, diuretics remain underutilized," the report says.
The report doesn’t say diuretics are appropriate in all cases, but rather that they always should at least be considered, Cziraky says. "When patients are on multiple drug therapies, diuretics are usually in that mix or should be strongly considered for that mix. That was a big point that came out in JNC 7 and has been coming out in more of the literature."
All the major studies published prior to the publication of JNC 7 were addressed and interpreted in the guidelines, Cziraky adds. "They were applied directly where they could be. If not, they were taken together as a group of literature."
Some health care specialists have said they believe the report might recommend diuretics too strongly, he says. "I know from discussions with the group and from knowing how the guidelines were developed that consideration of diuretics is appropriate, especially with combination therapies, and that there is a lot of room for clinical judgment."
The key is making sure to identify patients who are in prehypertensive states as well as those in hypertensive states, Cziraky says. "Once that happens, put the patients on the therapy and get them controlled in a relatively short period of time," he advises.
Another point emphasized in the JNC 7 report is that most patients will need two or more drugs to get to the desired blood pressure control levels, he says. "When blood pressure is more than 20/10 mmHg above goal, consideration should be given to initiating therapy with two drugs, either as separate prescriptions or in fixed-dose combinations," the report says.
The report makes a careful effort to support every recommendation for drug therapy with citations in the literature, Cziraky says. "If the clinicians want to look at those articles in more depth, the references are there, too. They have the ability to go back and do their own interpretations."
How can pharmacists help?
The JNC 7 report emphasizes the importance of physician judgment. The report, however, also recognizes the value of all members of the health care team, including pharmacists, working together to control hypertension.
"Failure to titrate or combine medications, despite knowing the patient is not at goal blood pressure, represents clinical inertia and must be overcome," the report says. "Decision support systems (i.e., electronic and paper), flow sheets, feedback reminders, and involvement of nurse clinicians and pharmacists can be helpful."
To assist in this goal, pharmacists need to be able to classify each of their patients according to the categories given in the new guidelines, Cziraky says. Pharmacists then can make recommendations either directly to the patient or to providers and practitioners about choice of agents based on the categorization.
Information about appropriate combinations of drug therapies is especially helpful, because most patients will be taking several drugs, he says. "Make sure your patients are aware of the importance of taking their medications and why taking two agents for the same abnormality makes sense because they work by different mechanisms."
Lifestyle changes, however, should not be neglected as an important part of the treatment mix. "It takes a lot of education and discussion with the patients to make them aware of the importance of intervening with their high blood pressure," Cziraky says.
Overall, the JNC 7 report is an excellent tool pharmacists can use to help them control their patients’ blood pressure, he adds. Pharmacists play a significant role in control of hypertension because they often see these patients most frequently and are thus in a good position to determine whether the patients are adhering to therapy. "There is a lot of opportunity for pharmacists to play a critical role in getting better control rates on elevated blood pressures in this country," Cziraky says. "They have a great chance to intervene and hopefully make an impact."