British case supports using Relenza in this as-yet-unapproved form, experts say
THURSDAY, Sept. 3 (HealthDay News) -- A 22-year-old cancer patient battling for her life after contracting H1N1 swine flu recovered fully after doctors took the unorthodox approach of giving her the antiviral drug Relenza intravenously.
The British physicians who treated the woman said this last-resort approach may need to be considered for others as swine flu sweeps the globe. Relenza is licensed in pill form and as an inhaled powder, but not as an intravenous medication.
In this woman's case, neither Relenza nor a similar H1N1-fighting drug, Tamiflu, could reach her severely affected lungs when taken orally or inhaled, the physicians report in the Sept. 4 online issue of The Lancet.
"There were clinical signs that the patient was not able to absorb the Tamiflu because of a problem with the digestive system; and in the case of Relenza, the lungs were very inflamed with a lot of fluid leakage, and we considered it likely that the powdered form of the drug was not able to penetrate far enough to be effective," explained study co-author Dr. Michael Kidd of University College London Hospitals.
The woman's situation was dire. She had been hospitalized in an intensive care unit for 16 days and was breathing through a respirator after her lungs filled with fluid. Also, her immune system had been badly weakened by the chemotherapy she was taking to help fight her cancer.
Since oral or inhaled medicines had failed to reach the woman's lungs, Kidd and his colleague, Dr. Mervyn Singer, turned to an unlicensed form of intravenous Relenza after consultations with the hospital and next-of-kin. "Giving the antiviral drug into the bloodstream would get round these obstacles, and we anticipated it would reach the lungs rapidly and effectively," Kidd said.
The treatment worked. After receiving the IV Relenza, the woman began to recover speedily, greatly reducing the amount of H1N1 virus in her system. Five days later, she breathed on her own, and in a little more than a week she left the intensive-care unit.
Singer and Kidd also gave the patient corticosteroids at the same time that she received the intravenous Relenza. "We reasoned that the steroids might help by damping down the inflammation once the viral replication was under control," Kidd said. "We have no evidence that this was the case in our patient, but we would like to see this possibility addressed in future clinical trials."
Their success in bringing this very sick patient back from the brink augurs for the wider acceptance of intravenous Relenza for patients seriously affected by the swine flu this fall and winter, Kidd said. "We consider it very important to further investigate this approach as soon as possible, since apart from the obvious individual patient benefit, it could help relieve the pressure on beds that is likely to occur in critical care facilities during the colder seasons," he said.
One U.S expert agreed. "The patient was deathly ill and [the doctor] got permission to use it on this patient, and then it seemed to have helped, and I think that's great," said Dr. Peter Gross, chief medical officer at Hackensack University Medical Center in New Jersey.
"The individual involved was at very high risk of having very serious complications of the novel H1N1 because the person was very immunocompromised," Gross pointed out.
The U.S. Centers for Disease Control and Prevention has placed people with chronic underlying illnesses, such as asthma, diabetes or cancer, and those with compromised immune systems high on the list of those at risk for severe or life-threatening H1N1 infections. Many of the 477 Americans who have died have had some sort of underlying medical condition, CDC officials noted Thursday in their journal, Morbidity and Mortality Weekly Report.
According to Kidd, the woman he treated exhibited no side effects from the strategy. "IV Relenza is well-tolerated in adults at quite high doses, previously shown in clinical trials, and it can be used in children from 6 months of age," he said. There are certain "contraindications" for its use -- doses may need to be adjusted if the patient has kidney disease, for example, and its safety during pregnancy "has not been established," Kidd said.
But even for pregnant women (another H1N1 high-risk group, according to the CDC), "in severe swine flu respiratory disease, the expected benefit to the mother is likely to outweigh any possible risk to the fetus," Kidd said.
Find out more about H1N1 flu at the U.S. Centers for Disease Control and Prevention.
SOURCES: Michael Kidd, FRC, clinician, University College London Hospitals NHS Foundation Trust, London, England; Peter Gross, M.D., chief medical officer, Hackensack University Medical Center, New Jersey; Sept. 4, 2009, The Lancet, online
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