The Health Corner Vol. 59 – Blood Pressure III
This is the third article in a series I have been writing on blood pressure. I have given a general overview on blood pressure and discussed the class of anti-hypertensives known as diuretics. Today I would like to discuss another group of drugs belonging to this class of drugs known as the beta blockers.
Beta blockers belong to the group of drugs known as anti-adrenergics. Anti-adrenergics (adrenergics referring to the adrenals which secrete the hormones adrenaline and noradrenaline, also known as epinephrine and norepinephrine, respectively) limit the action of epinephrine and norepinephrine, thereby relaxing the blood vessels and reducing the speed and force of the heart’s contractions.
Beta blockers have been used since the 1960’s. Their mechanism of action is to lock on to cell structures called beta receptors. These are the same receptors that certain neurotransmitters (primarily epinephrine) normally attach themselves to in order to stimulate the heart. You may be aware that when someone goes into cardiac arrest epinephrine or adrenaline (the same thing) might be injected directly into the heart muscle to stimulate contractions. That is the function of epinephrine in any human being, in cardiac arrest or not. Well, beta blockers will attach themselves to the beta receptors and inhibit epinephrine from activating the heart cells by tying up the beta receptor sites. As a result, beta blockers cause the heart rate to slow and blood pressure to fall.
Beta blockers come in two varieties: cardioselective and nonselective. Cardioselective beta blockers attach primarily to beta-1 receptors in the heart. Nonselective beta blockers attach to beta-1 receptors and beta-2 receptors, which are found in the lungs, blood vessels, and other tissues. Either type of beta blocker can worsen asthma or other chronic lung disorders, but the nonselective agents are potentially more dangerous for people with respiratory problems. Beta blockers can also worsen heart failure in some patients while improving it in others. They can also mask the warning signs of hypoglycemia (low blood sugar) in patients with diabetes.
The most common side effects of beta blockers are fatigue, depression, erectile dysfunction, shortness of breath, insomnia, and reduced tolerance for exercise. Realize that these are cardiac drugs, not just ‘blood pressure medicine’. Because they are cardioactive drugs one can expect signs of serious heart disease as another effect of taking them. These issues include congestive heart failure, which will lead to pulmonary edema, a good old-fashioned heart attack, or arrhythmias. All of these irregularities can be fatal. One may also experience a stroke, which could cause partial paralysis or death. And I already mentioned the danger to asthmatics.
Make no mistake about it, these drugs are cardiotoxic conpounds. If one is solely interested in lowering his blood pressure beta blockers will help to accomplish this function but the price paid in ones health is, in my estimation, quite high. So it is good to ask the question, ‘is the goal of lowering the blood pressure worth the damage incurred to the body, and in this case specifically the heart’?
We all understand that the medical hypothesis is that so-called ‘high blood pressure’ is harmful and lowering it is the primary goal at whatever the cost (financially as well as physically). As stated earlier in this series, once one buys into this paradigm and starts on blood pressure medication, over time the condition requires more and stronger drugs to keep the blood pressure ‘controlled’. Who benefits the most from this insidious cycle? In my considered opinion it is the pharmaceutical industry. And I believe that this occurs at the expense of the health of the individual who accepts this line of thought.
In the next article we will discuss the ACE inhibitors and calcium channel blockers as a means of controlling high blood pressure and the symptomology one can expect to experience when using them.
Until then, here’s to your good health!
Dr. Jon R. Link