Whenever there is any hemorrhage from any wound or site of surgery, normally, our body reacts very fast to stop the blood loss by closing up the ruptures caused in the blood vessels.
This happens in two phases - firstly, when the cells known as platelets gather in the form of wadding at the place where the wall of the blood vessel has ruptures; and, secondly, when these cells or platelets make and release chemical substances that trigger the factors related to clotting in the blood to develop a protein known as fibrin.
It is important to note that vitamin K plays a vital function in the process involved in forming blood clots. In addition, an enzyme present in the blood and known as plasmin makes sure that the clots disintegrate once the injury has been healed.
However, a few health problems get into the way of this process of forming blood clots. They may totally thwart the formation of blood clots or result in uncontrollable formation of blood clots. In such case, there are two risks.
First, preventing the formation of blood clots will cause loss of too much blood; while improper formation of blood clots may even result in blocking the blood from circulating to a very important organ.
The formation of the protein fibrin is subject to the presence of many proteins that are factors in blood clotting. If the factor VIII is totally absent or its level is very low, people suffer from an inherited ailment known as hemophilia.
It may be noted that the symptoms related to hemophilia more or less always occur exclusively in males. On the other hand, any deficit of factor IX results in a different bleeding problem known as the Christmas disease, which got its name from the individual who suffered from it first. Absence of these two blood clotting factors may result in unrestrained hemorrhage or too much bruising after sustaining an injury.
Generally, hemophilia does not need to be treated using medicines on a regular basis. However, in the event of severe hemorrhages or bruising, a physician may inject a concentrated variety of the lacking or deficient blood clotting factors, which are taken out from the usual blood with a view to support the formation of blood clot and also stem bleeding. In some cases, it may be necessary to repeat administering injections for a number of days after sustaining the injury.
Occasionally, promoting blood clot formation is useful even in people who do not suffer from hemophilia, especially when stemming bleeding is very difficult - for instance, following a surgery.
In instances like this, sometimes blood clots are stabilized by decreasing the actions of the enzyme called plasmin using an anti-fibrinolytic medication (also called hemostatic medications), for instance, aminocaproic acid.
Sometimes, this medication is also prescribed for people suffering from hemophilia before they undergo any small surgery, for instance, extracting tooth. In addition, some people may have a propensity to bleed, which is a result of vitamin K deficiency.
Generally, formation of blood clots occurs only following an injury. However, a number of people have a propensity to have clots in the blood vessels without any obvious reason.
The existence of deposits full of fat within the blood vessels (a condition called atheroma) enhances the possibilities of this kind of anomalous formation of blood clots (also known as thrombus).
Besides, this abnormality, a part of the blood clot (called embolus) developed in reaction to an injury or a surgery may get detached and circulate inside the bloodstream. Risks of this happening increases following prolonged periods of inactivity or very little activity.
Following the formation of the anomalous blood clot, there are chances that it possibly will get fixed in a place inside the blood vessel, thereby obstructing the supply of blood to a very important organ like the heart or the brain.
In order to put off the formation of such abnormal blood clots and even disperse them physicians normally prescribe three major varieties of medications - anti-coagulant medications, anti-platelet medications and thrombolytic medications.
People, who have a propensity to form abnormal blood clots inside the arteries and the heart, where blood flows very fast, use anti-coagulant medications on a regular basis. These medications are also prescribed to put off the formation of blood clots following a heart surgery. Anti-coagulant medications lessen the platelets' inclination to remain unified when the flow of blood is interrupted.
ASA is the most extensively prescribed anti-platelet medication. When given in extremely small doses that are inadequate to lessen pain, the action of this drug is anti-platelet.
This medication may cause unpleasant side effects when given in elevated doses to relieve pain, but they do not occur when ASA is used in such low doses. Sulfinpyrazone and dipyridamole are two other anti-platelet medications that are also used commonly.
Anticoagulant medications are prescribed for people who face the risk of forming abnormal blot clots. These medications assist in sustaining the usual blood circulation in such people and they are helpful in avoiding blood clot formation inside the veins.
Alternately, anticoagulant medications also help to make an already formed blood clot stable to prevent its disintegration and form a blockage (embolism) stopping blood circulation.
It may be noted that all medications called anticoagulants work to decrease the actions of specific factors related to blood clotting. However, the actual mechanism of each medication is different.
Anticoagulants are not helpful in dissolving blood clots that have already formed. Medications called thrombolytics are used to treat this problem.
Anticoagulant medications may be divided into two categories. The first group includes medications like enoxaparin and heparin which are administered in the form of injections and their action starts immediately. The second group of anticoagulants includes medications like warfarin, which are taken orally and their action starts after some days of taking the medication.
Heparin is an anticoagulant drug available in injection form and is primarily given to hospitalized patients either during or following a surgery. In addition, this injection is also administered while a patient is undergoing kidney dialysis with a view to check formation of blood clots inside the equipment used for dialysis.
It is important to note that heparin is never taken orally, but always administered subcutaneously or intravenously. The other anticoagulant injection enoxaparin is only administered subcutaneously.
Occasionally, heparin is also given to people before they begin regular therapy with any anticoagulant medication that is used orally.
Oral anticoagulants are primarily employed to thwart blood clot formation inside the veins and it has been found that these medications are unlikely to put off the blood clot formation in the arteries.
These medications are usually given to people following a surgery (especially, following replacement of heart valve) or after they sustain any injury, when they are at elevated risks of enduring embolism (a blockage that disrupts blood circulation). In addition, oral anticoagulant medications are also employed in the form of a preventive treatment for people who face the risk of having strokes.
Use of oral anticoagulants also poses a serious risk - when taken in excessive doses, they are likely to cause bleeding from the gums, nose or even in the urinary tract. An over dose of these medications may also result in bleeding form a minor bruise.
This is the main reason why the dose of oral anticoagulants ought to be measured cautiously and people taking them should have their blood examined on a regular basis to make certain that they can adjust the blood clotting system appropriately. Warfarin is the most extensively used oral anticoagulant medicament.
It is worth mentioning here that the oral anticoagulants may possibly interact with certain other medicines as well as foods that contain high amounts of vitamin K, for instance, green, leafy vegetables. Therefore, if you are using any other medicines, it may be necessary to change the anticoagulant dosage.
If your physician has prescribed an anticoagulant medication for you, it is advisable that you stay away from particular foods and always carry a list of medicines that should not be given to you, as they may possibly have an effect on the results of the anticoagulant you are using. It is important to note that unless your physician instructs you otherwise, ASA is one medication that should never be taken in conjunction with any anticoagulant.
Thrombolytics are also called fibrinolytics and they are employed to dissolve the existing blood clots. Normally, thrombolytics are given to people in a hospital in the form of an intravenous injection in order to unclog the blood vessels that have been obstructed by blood clots - for instance, in the case of coronary thrombosis. In addition to being administered intravenously, these medications can also be directly given into any blood vessel that is blocked.
Tissue plasminogen activator (tPA) and streptokinase are the two principle thrombolytic medications and they both work by augmenting the levels of plasmin - an enzyme that occurs naturally in the blood and which usually disintegrates fibrin, in the bloodstream.
The major risk associated with using these medications is augmented vulnerability to bruising and bleeding. In addition, use of streptokinase may result in allergies that may appear to be like urticaria (hives), breathing problems as well as swelling.
Vitamin K is necessary to produce a number of factors related to formation of blood clots. Normally, vitamin K is taken up from the fats in the intestines. However, in the case of a number of ailments related to the small intestine or the pancreas the absorption is not adequate resulting in low levels of vitamin K in the bloodstream and this causes formation of impaired blood clots.
At times, a similar problem develops in newborn infants owing to the dearth of vitamin K. In such cases, the babies are administered an injection form of vitamin K, known as phytonadione, to bring the levels of this vitamin to normal.
