WEDNESDAY, March 21 (HealthDay News) -- A new medication called
tenecteplase may be more effective at treating strokes caused by
clots in large blood vessels in the brain than the current standard
therapy, Australian researchers report.
"This study compares a newer thrombolytic medicine [tenecteplase] to the standard thrombolytic medicine [alteplase] in the treatment of patients with acute ischemic stroke," explained study author Dr. Mark Parsons, an associate professor at the University of Newcastle School of Medicine and Public Health and a senior staff specialist in neurology at John Hunter Hospital, in Newcastle.
Thrombolytic drugs are essentially clot-busters. The researchers
found that tenecteplase was better at restoring blood flow to the
brain after a stroke than alteplase. In addition, fewer people
treated with a higher dose of tenecteplase had a serious disability
at 90 days after their stroke compared to those on alteplase.
Results of the study are published in the March 22 issue of the
New England Journal of Medicine. Funding for the study came from the Australian National Health and Medical Research Council.
Acute ischemic strokes occur when a clot blocks blood supply to
the brain. Both tenecteplase and alteplase are from a class of
medications known as a tissue plasminogen activator (tPA). When
given within three hours of the first stroke symptoms, intravenous
tPA can open up the blocked blood vessel in the brain and prevent
further brain damage.
Recovery after receiving one of these medications can be fast
and dramatic, though this isn't always the case. And, excessive
bleeding is a significant risk factor associated with these
The current study included 75 people treated within six hours
after an acute ischemic stroke. All received advanced computed
tomography (CT) imaging to ensure that there wasn't any
stroke-induced brain damage yet, and the researchers also looked
for people who were having strokes in a large blood vessel.
Parsons said the researchers used the advanced CT screening to
"identify stroke patients with the greatest potential to benefit
from thrombolytic treatment."
The patients were randomly assigned to receive either a standard
dose of alteplase, or one of two different doses of tenecteplase
(0.1 milligrams (mg) per kilogram (kg) of body weight or 0.25 mg
per kg). A kilogram is about 2.2 pounds. All received the
medication less than six hours after the onset of symptoms,
according to the study.
Blood flow of both tenecteplase groups was restored more
effectively than for the alteplase patients. People in the
tenecteplase groups also showed greater clinical improvements than
those on alteplase after 24 hours.
The higher dose of tenecteplase appeared to be more effective.
After 90 days, 72 percent of those treated with the higher dose of
tenecteplase were free of serious disability compared to just 40
percent of those on alteplase.
There were no significant differences in excessive bleeding in
the brain or other serious adverse events, according to the
"The perfect clot-busting drug would open up the blockage without causing any hemorrhage. Short of that, the goal is to find a drug that works at least as well, if not better, and that's as safe," said Dr. Keith Siller, director of the Comprehensive Stroke Center at NYU Langone Medical Center in New York City.
"They showed that under ideal circumstances, this drug works well. It still remains to be seen if other types of strokes will be helped as much," said Siller.
Hemorrhagic strokes, which occur when a blood vessel in the
brain bursts, are less common than ischemic strokes.
Parsons said he and his colleagues hope to broaden the study
population in their next study. They said the current findings
warrant moving on to a study comparing the drugs' performance
within a shorter window for treatment.
Siller said that while researchers are trying to refine the type
of clot-busting drug that might work best, the message to the
public remains clear: If you have any symptoms of stroke, get to
the hospital as soon as possible.
"All of these treatments require patients to come to the hospital as soon as possible," noted Siller, who added that treatments currently need to be administered within three hours after the onset of symptoms.
Learn the warning signs of stroke from the
National Stroke Association.