Stroke Treatment-Part II
AstraZeneca PLC's, the British pharmaceutical company announced that it would launch a large-scale test of its new stroke treatment drug Cerovive. Scientists at the company hope to show that the drug will be effective if administered within 6 hours after onset of a stroke. Up until now one of the most common treatments for stroke victims involve the administration of the clot dissolving agent known as tissue plasminogen activator, or TPA, but it must be given to a patient within three hours of the onset of the stroke.
The company's expanded trials involving 3,000 patients are intended to see whether Cerovive can counteract some of the debilitating affects suffered by acute-stroke patients. Two separate phase-3 trials will take place. The first, SAINT-1 involves 200 sites across 24 countries in Europe, Asia, Australia and South America. The second, SAINT-II will involve 150 sites in the U.S., Canada and South America. Cerovive is licensed from Renovis Inc. of South San Franciso, Calif.
Cerovive is the first of a new class of medicines called nitrones. It acts like a sponge and attaches to free radicals and forms a new molecule. The drug was given to rodents as much as 5 hours after the onset of an induced stroke and the drug appeared to save about 80% if the animals brains that would otherwise have died. When given to primates as late as 4 hours after an induced stroke, some 50% to 60% of the brain area was saved.
A European study done on the effects of AstraZeneca PLC's new drug Exanta, showed that it may be safer and more effective for treating heart patients with atrial fibrilltion who are at risk of stroke than is Bristol-Myers Squibb Co.'s warfarin (Coumadin). Warfarin is presently the gold standard for treating the problem.
Warfarin is difficult to administer and can cause side effects, such as internal bleeding. Johnathon Halperin, a cardiologist at Mount Sinai Medical Center in New York spoke on behalf of the investigators. Overall, patients in the 3,407 patient trial who took Exanta suffered a stroke, major bleeding or death at a rate of 4.6% a year compared with 6.1% for the patients on warfarin. Patients taking the Exanta were far more likely to exhibit elevated liver enzymes within the first six months of the trial, but the problem went away with the cessation of the treatment. It is estimated that about two million Americans suffer from atrial fibrillation. About 15% of all strokes occur in people with atrial fibrillation.
The Journal of the American Medical Association reported on the results of 2 different studies that involved the clot dissolving drug Activase, also known as tPA, and its affect on stroke patients. In one of the studies the researchers looked at the treatment of 3,948 stroke patients admitted to Cleveland area hospitals from July 1997 through June 1998. TPA is regarded as being helpful only if administered within 3 hours after the initial stroke. Only 70 of the patients fell within this grouping. Those who received the drug had 15.7 % mortality, more than three times the death rate among stroke patients who didn't get the drug. Thus although tPA lowers by about 13 % the rate of lingering disability from stroke is it worth the risk from the increase in the mortality rate? tPA is the only drug approved by the Food and Drug Administration for treatment of acute stroke caused by blood clots.
The second study involved researchers at multi-center hospitals including Stanford University Medical Center and at 23 other academic hospitals and 33 community hospitals. The doctors involved in this study adhered to the strict guidelines involved when tPA is to be administered, The drug should be administered to patients with "ischemic" stroke caused by a clot since the drug is an anticoagulant, and not to those who have "hemorrhagic" stroke. This study concluded that if the strict guidelines are adhered to tPA, 43% of the tPA patients were functionally independent within 30 days.
Stroke is a type of brain injury that is frightening to both the patient and the family. It is caused by reduced blood flow to the brain as result of blockage or the leaking of blood into the brain following the bursting of a blood vessel. You may have ischemic stroke (blood vessels blocked by clots or the vessel is too narrow for blood to get through), or a type of stroke called hemorrhagic stroke (where the blood leaking into the brain causes damage to surrounding cells). A major goal of any treatment would be to limit the extent of damage, or find ways to reverse the extent of the damage. Drugs are presently available that are effective when the stroke is treated within three hours of its occurrence. Researchers now appear to have found a method to counteract the effects of a stroke after this initial phase.
Sandra Blakeslee, a science writer for the NY Times reported (February 2, 1999), in an article entitled "New Therapy Helps Some Stroke Patients", on a treatment regimen involving use of amphetamines and physical therapy. What this treatment does is nudge the process along by taking advantage of the "plasticity" of the brain. This involves the brain's capability of making new connections under the right conditions. The object of the treatment would be to create the right atmosphere for the brain to create new connections.
What appears to happen during a stroke is that many neuron cells in the areas around the site of the stroke are stunned rather than killed. They can no longer deliver the message to their neighboring dead cells or receive messages from them. When you treat a stroke victim with amphetamine it causes the release of noradrenaline throughout the brain. This acts as a modulator, arousing the stunned neurons into action, promoting new nerve connections.
At the same time, there is a need for physical therapy to be part of the treatment. This finding stems from the work of Dr. Dennis Feeney, a professor of psychology and neuroscience at the University of New Mexico. In studies done with rats, Dr. Feeney found that amphetamines work when the animal is free to move around. When prevented from moving, they did not improve. It is the combination of the two factors that brings on the effect. This was confirmed in clinical trials with humans.
According to the NY Times report, it is important to "push" patients to their limits in physical therapy for this treatment to work. Quoting from the article: "Treated patients achieve in six weeks what usually takes six months to achieve. Patients taking dummy pills tend to reach a plateau after a few months of physical therapy. A year later, long after both groups are not taking pills, the patients who took amphetamines are far ahead of those who did not."
The NY Times article cautions that this treatment is experimental and that it may not be appropriate for elderly with heart disorders or other serious ailments.
Stroke is a terribly disabling disorder effecting about 730,000 individuals each year. Any step in alleviating the residuals of this event is a welcome addition to the rehabilitation process.
The Wall Street Journal reported on February 5,1999, that a drug in experimental stage may help patients fully recover from severe strokes when treated as late as 6 hours after the onset of symptoms. The drug has been developed by Abbott Laboratories and is called prourokinase. Dr. Anthony J. Furlan is heading the study at the Cleveland Clinic.
The American Heart Association indicates that the following are warning signals of stroke:
For further information on stroke call 1-800-553-6321. The
American Heart Association can be reached at 1-800-242-8721.
On September 13, 1999 we received the following e-mail from a viewer pertaining to a product that she found beneficial in connection with the rehabilitation process in connection with her husband's stroke. Remember we do not recommend the product, we only bring it to your attention so that you may check out this matter yourself. Please go to Tate e-mail
Stroke Part I General Information
Stroke Part III : Reducing Risk
Stroke Part IV-Role of aspirin and heparin in ischemic stroke
FOR AN INFORMATIVE AND PERSONAL ARTICLE ON PRACTICAL SUGGESTIONS WHEN SELECTING A NURSING HOME SEE OUR ARTICLE "Selecting a Nursing Home"
Harold Rubin, MS, ABD, CRC, Guest Lecturer
Updated June 5, 2003
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