Role Of Beta Blockers In Hypertension

Hypertension is considered one of the top causes of mortality today due to its action and involvement of multiple organs in the body. Generally a blood pressure reading of 130/90 or above is regarded as hypertension, but in order to confirm the diagnosis, it is important to take the blood pressure at two separate occasions or timings.

What are Beta blockers?

Due to high risk of mortality as a result of untreated high blood pressure, a number of medications and drug therapies have been formulated and to this date new therapies and formulas are being devised to achieve the blood pressure control, but so far the greatest discovery is of Beta Blockers.

Beta blockers are considered Class 2 of anti-hypertensive medications and are considered an excellent choice in controlling blood pressure within optimal ranges. There are many drugs that follow the methodology and mechanics of beta- blockers. These include Metoprolol, Sotalol, albuterol and many others. The type of drug and dosage is advised after the doctor’s prescription and involvement of other systemic issues.

What is the mechanism of action of Beta blockers?

 

Role Of Beta Blockers In Hypertension
By: USAG Livorno PAO

Beta blockers are known for their strong influence on Beta receptors of heart and blood vessels. Once the active ingredient of medicine is released in the blood, it helps to normalize the blood pressure by:

Dilating the blood vessels so that the caliber of arteries is increased and the force of blood flow is minimized.

Beta blockers have their main course of action on cardiac tissues by increasing the force of contraction. This allows the heart to beat more forcefully in order to act as a better pump.

These functions are achieved by interfering with the epinephrine action in the heart and blood vessel.

What are other indications of Beta Blockers?

Beta blockers are an effective and relatively safe drug to consume in some special circumstances. One is definitely essential hypertension that is the biggest and commonest variety of hypertension and reported in more than 95% of the patients. Moreover, Beta blocker is a preferred choice in cardiac patients due to its action of improving the contractility and functioning of heart. This property and functioning makes beta blocker as the first line therapy of congestive heart failure.

Apart from cardiac illness, beta blockers can also be used for:

Glaucoma:

Glaucoma is an optical condition of the eye that is fairly painful and may also affect vision in long term cases. Due to the action of beta blockers on blood vessels, it can also enhance the drainage of aqueous humor from the eye, eventually relieving watering of eye and redness.

Migraine:

Beta blockers are an excellent choice for those who have concurrent high blood pressure complaints along with migraine headache history. The mechanism of relieving headache is the same i.e. enhancing the blood flow across the blood vessel and dilation of arteries.

Along with that, beta blockers also treat anxiety disorders and rhythm abnormalities co-existent with high blood pressure. Currently, the most recommended drug for cardiac and vascular effects of hyperthyroidism is beta blocker that is not only safe but also effective and abolishes the need for a second drug. However, if proper control of blood pressure is not achieved by beta blockers alone, a second drug can always be added.

Limitation of Beta blockers:

There are a few conditions in which beta blockers cannot be advised, due to high risk of morbidity and mortality in the patients. These are:

Diabetic patients:

Beta blockers are contraindicated in diabetic patients. This is mostly because it becomes hard to detect clinically if the patient is experiencing hypoglycemic symptoms or heart failure symptoms. The characteristic or classic features of both these conditions are the same and include profuse sweating, twitching of muscles, loss of consciousness, pain in abdomen and cold sweating. A very few people experience cardiac arrests with beta blocker dosage, which is why it is not indicated to give beta blockers to diabetic patients. In addition, since glucose blood levels are also modulated by some beta receptors, the glycemic control may be deranged with simultaneous use of hypoglycemic drugs and beta blockers at the same time.

Kidney patients:

Beta blockers are also contraindicated in kidney patients due to interference of renal blood supply. In patients with co-existent cardiac condition and renal impairment, ACE inhibitors (Angiotensin Converting Enzyme inhibitors) or ARB blockers are preferred over beta blockers.

Asthma or lung disease:

Asthma or serious lung disease is a serious contraindication to the use of beta blockers. This is because lungs also has beta receptors and blocking the action of beta receptors will lead to an asthma attack that may prove life threatening if not timely controlled.

Drug interactions:

Prescribing beta blockers must require a pre-assessment of liver and renal functioning. This is because the mode of metabolism and excretion of most beta blockers is via liver or kidney. In case of any serious functional impairment, the drug will have difficulty in being excreted fully from the body leading to high levels of functional drug molecules and chemicals in the body that may lead to a sudden cardiac arrest or death. In all such patients, a dose adjustment is needed with tight monitoring of active drug molecules in blood and urine.

It is also worth mentioning that beta blocker levels are likely to get altered by concurrent consumption of some drugs particularly antibiotics that enhance liver enzymes resulting in altered metabolism of beta blockers by the liver.

How to take beta blockers?

For best results and in order to achieve better blood pressure control with anti-hypertensive therapy, it is suggested to consume a low salt diet that is low in sodium to avoid a spike in blood pressure. It is also recommended to maintain your weight within normal range to minimize resistance to the flow of blood and for better cardiac health. Lastly, physical activity and moderate exercise is the most essential element that determines the response to therapy with beta blockers.

It is strictly advised to consume beta blockers with the advice of your healthcare provider. This includes the type of beta blocker and the dosage.

Make sure to follow the drug regimen religiously.

Do not take more than the recommended dosage

Monitor your blood pressure regularly while taking beta blockers and in case of any abnormalities or irregularity in the values, consult your healthcare provider for the adjustment of dosage.

Keep up with all the visits with your doctor to see if your blood pressure is controlled and you are not developing any complications due to blood pressure or drug usage.

What are potential side effects of beta blocker therapy?

Beta blockers are generally safe but in some patients, these minor side effects can be seen quite frequently that neither require dosage adjustment or stopping the therapy and in most cases are relieved by their own in a few weeks.

These are excessive fatigue, weakness or generalized malaise that is not associated with any activity. You may also experience a sensitive stomach ranging from mild constipation top diarrhea but once again requires no additional therapy or dose adjustment.

Some serious side effects may also be seen that require dose adjustment or change of therapy; these are:

Issues with sex drive or loss of libido

Issues in mental status changes, mood changes or similar issues. This is because beta blockers may also lead to depression; however this is not a common side effect.

Disturbed sleep may also occur during early beta blocker therapy.

When you must see a doctor?

Generally it is recommended to see a doctor regularly with active high blood pressure and beta blocker therapy once a month at least or as suggested by your healthcare provider. On the other hand, in the following situations there is a need to see your doctor as early as possible to minimize any catastrophic episode.

If you are having severe pounding headache , unprovoked and refractory to any pain killer therapy

If you are having palpitation or irregular heartbeat, heart rhythm or any similar symptom.

If you are developing chest pain or excessive sweating.