A Whole New Approach to Stroke Treatment and Prevention
Drug therapy is a relatively recent approach to the treatment of stroke, and a tremendous amount of research is currently underway to find effective new drugs that can minimize stroke damage. Many of these new drugs are showing promise, not only for the emergency treatment of stroke, but also for stroke prevention.
Drug Therapy for Emergency Stroke Treatment
Among all treatments available to combat stroke, perhaps the most revolutionary is the drug tPA (tissue plasminogen activator), the only FDA-approved drug for treatment of stroke. Originally developed to treat heart attacks, tPA is known as a "clot-buster" because it can literally stop an ischemic stroke as it is happening by breaking up the blockage and restoring blood flow to the brain.
This drug has the potential to significantly minimize and even reverse the effects of stroke if administered intravenously within the first three hours of the onset of symptoms. The American Stroke Association reports that less than five percent of people who might benefit from tPA reach the hospital in time to receive it, largely due to lack of knowledge about stroke symptoms and the necessity of urgent treatment.
Ischemic stroke patients who have missed the three-hour window for intravenous tPA may still benefit from the drug, however, thanks to new technology that allows doctors to work inside blood vessels in minute detail. An experienced Norton Stroke Care physician inserts a catheter - a soft, narrow, plastic tube - into an artery in the arm or leg and guides it to the brain with the use of X-ray imaging. The clot-busting tPA is then injected near or directly into the clot to stop the stroke. This advanced procedure, known as intra-arterial thrombolysis, allows much less of the drug to be used and directs it to the exact site of the problem, yielding many positive results for the patient. This form of tPA must be given within six hours of the brain attack's onset. For those suffering hemorrhagic strokes, the same technique can be used to deposit tiny blocking agents, such as plastic balloons, or steel or platinum coils to stop the bleeding in the brain.
Drug Therapy for Stroke Prevention
In addition to the clot-dissolving drugs used for acute stroke treatment, medications that make the brain more resistant to stroke are being evaluated in clinical trials nationwide. These drugs, called neuroprotective agents, have the potential to make the brain less susceptible to the damaging effects of stroke, and many look promising for brain attack prevention.
A number of medications that can help prevent stroke in high-risk patients, particularly those who have had previous transient ischemic attacks (TIAs) or minor strokes, also are currently under investigation.
These drugs fall into two main categories:
Anticoagulants - (such as heparin, Coumadin, warfarin, ximelagatran and Exanta) may be given orally, intravenously or subcutaneously. These drugs work by thinning the blood to help prevent clotting. They also are used for treatment and prevention of deep vein thromboses and pulmonary emboli and are very effective in helping to prevent stroke in patients with atrial fibrillation, or an abnormal beating of the upper chambers of the heart.
Antiplatelet agents - (such as aspirin, Persantine, dipyridamole, Plavix and clopidogrel) work by preventing or reducing a phenomenon known as "platelet aggregation" in the bloodstream. When a blood vessel is damaged or injured, blood particles known as platelets migrate to the scene to initiate a healing process. Large numbers of platelets clump together and essentially form a plug. This clumping can sometimes result in the formation of a blood clot that may totally block the artery or break loose and block a smaller artery. By preventing this from occurring, antiplatelet agents can reduce the risk of stroke in patients who have had TIAs or prior ischemic strokes.