Uncertainties about proper use and possible long-term effects of hydroxyurea in the treatment of sickle cell anemia may be wrongly influencing doctors to avoid prescribing it to those in serious need, according to results of a literature review by specialists at Johns Hopkins.
"We know that many people with sickle cell disease aren't being offered this drug, which is the only one we have to treat this disease," says Sophie Lanzkron, M.D., assistant professor of medicine and oncology at the Johns Hopkins University School of Medicine and director of the Sickle Cell Center for Adults at Johns Hopkins.
In a bid to heighten awareness about the nature of the uncertainties and correct clinical use of the drug, the U.S. Department of Health and Human Services selected Lanzkron and her colleagues at Johns Hopkins to gather information from previously published studies on hydroxyurea.
First, they combed through databases to select randomized clinical trials, observational studies and case reports that evaluated the drug's effectiveness and incidences of toxic side effects. They excluded the poorer quality data and non-English publications and carefully analyzed data from 246 articles.
What emerged, the researchers say, is a clear picture of the drug's effectiveness.
Specifically, they found that the number of intensely painful sickle cell "crises," caused when misshapen, "sickled" red blood cells clump in blood vessels, dropped by 68 to 84 percent in people taking hydroxyurea. Their hospital admissions declined by 18 to 32 percent.
On the biological side, amounts of fetal hemoglobin, a blood component that seems to decrease sickle cell symptoms, increased by 4 to 20 percent after patients began taking hydroxyurea.
On the negative side of the risk/benefit ledger, studies in mice also indicated that hydroxyurea impairs sperm development. The researchers concluded that this effect could be present in hu
|Contact: Christen Brownlee|
Johns Hopkins Medical Institutions