FRIDAY, May 16, 2003 (HealthDayNews) -- A drug developed to quickly control bleeding in hemophiliacs appears to have wider uses, especially in situations where swift bleeding control is essential but difficult, such as severe trauma and some surgeries.
The drawback is cost. At $6,000 a vial, use of the drug -- NovoSeven -- is not always practical.
"NovoSeven, which is a Factor VII accelerant, is a very expensive, very effective way of treating bleeding in patients with Factor VIII inhibitor, but there is indication from other studies that it may have a much broader use," says Dr. Marcus E. Carr Jr.
Carr, from Virginia Commonwealth University Medical Center, notes one of the problems has been determining the right dose and showing that it is effective.
"This is important because the drug is so expensive, it is not appropriate for all patients," he adds.
Carr and his colleagues have developed a test that shows how NovoSeven works in normal blood and in blood taken from patients with different types of hemophilia, according to their paper in the May issue of Thrombosis and Heamostatis.
"We looked at clotting in whole blood, not in plasma alone, as is done in most other studies," Carr says. Platelets in whole blood are essential for clotting and this new test measures how strong the platelets are. NovoSeven improves the production of thrombin, which in turn strengthens the platelets faster than normal, he notes.
However, the optimal dose remains unclear. "The correct dose will probably vary from patient to patient and from condition to condition. In certain situations, a higher-than-recommended dose is called for, while in other situations a lower-than-recommended dose is better. This study shows that there are ways to determine how well the drug is working, so we should be able to tailor the dose to individual patients," Carr says.
The study was funded in part by Novo Nordisk, the makers of NovoSeven.
In another recently completed study, Carr's team found the test is useful in determining the dose not only of NovoSeven but other drugs used to treat bleeding disorders.
NovoSeven is being used in certain trauma situations and in surgery where there is extensive bleeding, although the U.S. Food and Drug Administration hasn't approved the drug for these purposes. In the future, NovoSeven will be more widely used for these applications, Carr predicts.
But Dr. Nigel S. Key, from the University of Minnesota, is skeptical. Key and his colleagues have developed a similar test based on activated clotting time, which they think is a better way of determining dosage.
"The truth is that neither Carr nor I know for sure if his test is accurate, because there is no clinical data to confirm what was found in the test tube," Key says.
Until clinical data are available, "it is not certain that what is found in the test tube will correlate with clinical outcomes," he adds.
Key believes NovoSeven works in some circumstances. However, he says it's still too early to determine whether it works in conditions other than hemophilia.
More information
To learn more about hemophilia, visit the National Hemophilia Foundation. To learn more about blood clotting, check with Indiana State University.
