The blood circulation becomes less effective when the heart fails to pump blood (a condition called heart failure) or in case of any abnormality in the heart rhythm (called arrhythmia). Besides, accumulation of fatty deposits in the blood vessels (a condition called atherosclerosis) may result in the narrowing and blockage of these vessels. As a result of these conditions, there may be diminished blood supply to the brain, the terminal extreme parts of the body (also referred to as peripheral vascular disease); or to the muscles of the heart (coronary heart disease) resulting in angina pectoris. The last two disorders - peripheral vascular disease and coronary heart disease may become further complicated owing to development of blood clots that possibly will obstruct the blood vessels. When this happens in the arteries, the vessels that carry blood to the heart, it is called coronary thrombosis, and it is the most common cause for stroke when it occurs inside the brain.
In addition to the above mentioned problems, hypertension or exceptionally high blood pressure is a very common disorder of the circulatory system. In the instance of hypertension, the pressure of the blood circulating through the vessels is very high on the walls of these vessels. Although the precise reason for the augmented blood pressure on the vessel walls is yet to be comprehended fully, scientists believe that the loss of suppleness of the walls of the blood vessels (a condition called arteriosclerosis) is one reason for this.
The term digitalis is used to denote several substances that occur naturally and are present in the leaves of plants belonging to the foxglove family (also referred to as cardiac glycosides) and employed to treat particular problems related to the heart. The major medications belonging to this group include digitoxin and digoxin. Between these two medicines, digoxin is used more extensively, as it is a short-acting medicament (the effect remains for a brief period) and also because adjusting the dosage of this medication is easier.
Electrical impulses or stimuli that are produced in the nerve tissues inside the heart cause the heart to beat normally. These impulses are responsible for the contraction of the heart muscles as well as pumping blood. Digitalis works to decrease the transmission of these electrical impulses within the heart, thereby making the heart to beat further leisurely.
The force used in contracting the muscles of the heart is dependent on the chemical modifications inside these muscles. Digitalis works to encourage such chemical changes and every time the electrical impulses stimulate the heart, the cardiac glycosides augment the power with which the heart muscles contract. This balances the power lost in stimulating some muscles that have been impaired because of a heart attack. When the heart beats robustly, it results in augmented blood circulation to the kidneys, which, in turn, boosts production of urine and, at the same time, assists in getting rid of the surplus fluid that usually builds up in the body following a heart failure.
Digitalis is very effective in providing relief from the symptoms associated with heart failure, for instance, breathing difficulty, exhaustion and swelling in the legs. It also enhances one's capability to undertake exercise and also increases the rate of recurrence of passing urine normally.
The downside of medications belonging to the class called digitalis medications is that they may also turn out to be toxic and provided the blood levels of the person using them is very high, they may cause symptoms of a condition known as digitalis poisoning. The symptoms of this condition may include extreme fatigue, poor appetite, vomiting, diarrhea, nausea and even confusion. You need to contact your physician right away and notify him/ her about these symptoms as soon as they appear.
In the normal course, the kidneys are responsible for eliminating digoxin from the body. However, in case the functioning of the kidneys is damaged, this medication may accumulate inside the body and result in toxic side effects. The liver breaks down digitoxin and is preferred to digoxin because this normally does not accumulate in the body. However, digitoxin can also build up inside the body following repeated dosages, particularly when the functioning of the liver is impaired or less efficient.
Both the digitalis medications - digitoxin and digoxin - become additionally toxic when the level of potassium in the bloodstream is low. Normally, use of diuretic medicines is responsible for a deficiency of potassium. Therefore, it is essential for people taking diuretics along with digitalis medicines to monitor the actions of these medications as well as the potassium level in their bloodstream carefully. In case any such person suffers from extreme potassium deficiency, he/ she may require taking supplements containing this essential mineral.
The hormone epinephrine produced by the adrenal glands and substances similar to it partially work by means of the beta receptors present in our body. Beta blockers (often referred to as beta adrenergic blocking agents) check the exploits of all substances similar to epinephrine on these beta receptors. Beta blockers are principally used to treat heart disorders, but sometimes also used to treat additional health conditions.
As the beta blockers oppress the actions of the beta receptors, they annul the actions of a neurotransmitter called norepinephrine. Hence, the beta blockers also lessen the power as well as the pace of the heart rhythm, put off the blood vessels around the brain as well as those carrying blood to the extremities from dilating, and also check the widening of the air passages to the lungs.
When used to treat angina pectoris (heart pain), beta blockers work to lessen the rate as well as the seriousness of the attacks. They are also used along with other medications to treat hypertension, because beta blockers help in lowering blood pressure and, hence, lessen the occurrence of symptoms related to high blood pressure. In addition, beta blockers are also useful in putting off serious bouts of arrhythmia that may be caused by abnormal or very fast heart rhythm.
Since beta blockers have an effect on several body parts, they generally result in trivial side effects. Beta blockers less the rate of heartbeat as well as the passage of air to the lungs and, hence, they are likely to decrease one ability to undertake exhausting exercises. However, this change may not be apparent in people whose aptitude for physical activities may have been restricted from before owing to problems related to the heart. Many people using beta blockers may experience coldness of their hands as well as feet, as the blood circulation to the limbs is greatly reduced by these medications. It is important to note that decreased blood supply may result in short-term impotency while one is undergoing treatment with beta blockers.
However, use of beta blockers also involves certain risks, the most important of them being breathing difficulties, because these medications also act to block the beta receptors present in the lungs. It is believed that using cardio-selective beta blockers that mainly affects the heart result in fewer such side effects compared to the non-cardiac-selective beta blockers. Nevertheless, while prescribing any beta blocker physicians take additional care in the case of people who are suffering from bronchitis, asthma or any additional type of disease related to the respiratory system.
Normally, physicians do not prescribe beta blockers for individuals having a poor blood circulation to their limbs, as these medications further decrease the blood flow to these body parts and may possibly also make other conditions endured by such people worse. Generally, beta blockers are also not recommended for people who have had a heart failure, as these medications may lessen the force with which the heart beats further. If you are having diabetes and require taking beta blockers, you ought to know that you may observe some changes in the indications of low levels of blood sugar; especially these medications may stifle the symptoms like quivering and palpitations.
Provided you have been using beta blockers for a prolonged period of time or even otherwise, you should not discontinue these medications abruptly, as this may aggravate an unexpected and acute reappearance of the symptoms associated with the initial disorder, or a heart attack too. In addition, if you stop taking the beta blockers all of a sudden, it may also result in a marked rise in your blood pressure. When you require stopping treatment with beta blockers, you should reduce the dosage of the medications gradually under the direct supervision of your healthcare provider.
Vasodilators are medicines that work to dilate or widen the blood vessels and they are usually recommended to treat disorders wherein the constriction of blood vessels result in diminished blood circulation, as a result of which lesser amount of oxygen is supplied to different body parts. Such medical conditions include angina pectoris, wherein the coronary arteries constrict so much that it leads to very poor supply of blood to the heart resulting in an excruciating spasm. Other such conditions comprise peripheral vascular disease, when contraction of the blood vessels leading to the limbs does not provide sufficient amounts of blood as well as oxygen to the terminal body parts (also known as extremities). In addition, vasodilators are extensively employed in treating hypertension (high blood pressure) and heart failure.
There are many different classes of vasodilator medications and they include ACE inhibitors (also called angiotensin-converting enzyme inhibitors); calcium channel blockers; sympatholytics and nitrates.
Vasodilators act to expand the blood vessels by means of unwinding or loosening the muscles surrounding them. These medications accomplish this by having a direct influence on the activities of the muscles (calcium channel blockers and nitrates work in this manner) or by obstructing the transmission of nerve signals that regulate the blood vessels constrictions (sympatholytics work in this manner). On the other hand, vasodilators belonging to the class of drugs called the ACE inhibitors work by obstructing the actions of enzymes in the blood.
Besides providing relief from the symptoms of the problems for which they are generally used, vasodilators may also produce some insignificant unpleasant side effects that are associated with their exploits on the circulation of blood. Side effects like headaches and flushing are widespread during the initial stage of treatment with these medications. In addition, people taking vasodilators may also experience light-headedness and even fainting owing to reduced blood pressure. You should also know that when the blood vessels are dilated, it may also result in the accumulation of fluids in the body, causing swellings, especially in the ankles.
One downside of using vasodilators is that they may result in a very sharp decline in blood pressure. This is the main reason why physicians take great care while prescribing vasodilators for people whose blood pressure is unstable. Hence, it is recommended that when you take these medications for the very first time, you should take it in such a place and such a time when you can sit down or lie after taking the dosage.