Questions and Answers on Hypertension Control

by Larry Weinrauch, M.D. Health Professional

1 . I can't get my blood pressure under control, why?

2. I am taking Cozaar for high blood pressure. Some days my readings aren't too bad but there are days with very bad readings. I am taking Hawthorn and yesterday my blood pressure was very high, so I decided to take a table (sic) of Potassium, and today I repeated. I wonder if the intake of Potassium will interact with the Cozaar.


There are several issues involved in these very common questions. The first, and most often a problem, is how often should blood pressure be taken, and what do day to day and minute to minute blood pressure variations mean. This is relatively easy to answer. Blood pressure varies throughout the day, usually rising in the morning just before we wake up and dropping during our sleeping hours. In addition, if we are very active, the blood pressure will rise and drop down afterward, as we rest. For this reason, measuring the blood pressure several times a day can be confusing. The pressure should always be measured while resting, at the same time, in the same arm, and the same way once per day. The numbers should be written down and a physician should go over them to make sure that they are in a good range for you. If you have known kidney disease, heart disease or diabetes, blood pressures should be below 130/70. It is not the single days measurements that is important, it is the accumulation of all the days. I generally tell patients not to measure the blood pressure more than twice a week and to let me know if their blood pressures are above a certain range (this can be done by phone once I have a feel for the patient and the problem). I do like patients to monitor their own health, but just like weighing yourself, doing it too often can only lead to problems, not good results.

The second question involves the important interaction between the patient, the doctor and the drugs. Less than half of all patients with high blood pressure can be adequately controlled on a single medication. No patient can expect to achieve good blood pressure control if medications aren't taken, or if blood pressure is not measured. Some patients will not achieve good blood pressure control if they continue to do things that increase the blood pressure (the pills don't work as well if you take antidotes to them such as a high salt (sodium) diet, heavy smoking, inadequate control of sugars if you are a diabetic, or if you take prescribed or non prescribed drugs, whether "natural" or not).

Cozaar (losartan) acts as an angiotensin receptor blocker. Angiotensin is a chemical that the body makes that constricts blood vessels and raises the blood pressure. One of the effects of the medicine losartan may also be to raise the blood potassium. In certain people, with a high intake of potassium or with decreased ability to excrete potassium, life-threatening arrhythmias can occur. THERE IS NEVER A NEED TO TAKE AN ORAL POTASSIUM SUPPLEMENT UNLESS YOU ARE UNDER THE CARE OF A PHYSICAN AND GETTING REGULAR BLOOD TESTS. The only reason that a physician should ever prescribe oral potassium is if you are losing it due to diuretic use, kidney loss (certain problems with the kidney called potassium losing nephropathy can do this), or certain bowel disorders (potassium losing enteropathy). Remember that although the right amount of potassium in the body is important, potassium is the poison that is used to stop the heart when prisoners are given lethal injections. Small doses may be safe, if the product is used as a "salt substitute" as part of a low sodium diet. Potassium supplementation is never indicated to reduce blood pressure or prevent muscle cramps.

Hawthorn is a plant product that has not been found to have any benefit in the control of blood pressure. There are no clinical trials that are convincing with respect to this formulation being helpful in any clinical cardiac condition. While there are a few trials of this agent in German journals, they are small and unconvincing. Although most such agents are tried and tried again for their "medicinal properties" because they are plentiful and inexpensive, many lesser "naturceuticals" are never demonstrated to be beneficial. Those that are generally become part of the regular pharmaceutical armamentarium (examples include foxglove (digitalis), certain tree barks (taxol, quinine), ergot and belladonna alkaloids). The absence of any good clinical trials means that this product has not been tested in the presence of medications that have true benefits. As such, it is possible that it is interacting with your prescribed medicines in a conflicting manner. When this happens, blood pressure may even increase. Always tell your physician if you are taking additional "natural" products. Doctors do have resources to tell if there is any interaction. One warning that I must give, time and time again, even to University professors: your doctor likely has 10 years or more of postgraduate training, often decades of experience with medications that neither you, nor the people promoting over the counter products have, use caution in adding any product for health without further discussion.

Larry Weinrauch, M.D.
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Larry Weinrauch, M.D.

Larry Weinrauch is a cardiologist in Watertown, Massachusetts and is affiliated with Mount Auburn Hospital. He wrote for HealthCentral as a health professional for Heart Health, High Blood Pressure, and High Cholesterol.