The antiviral drugs Tamiflu and Relenza should be used only to treat patients who are sickened by the pandemic H1N1 influenza virus and are at high risk from complications and should not be used prophylactically in people who have simply been exposed to the virus, officials from the Centers for Disease Control and Prevention said this morning. But patients with underlying medical conditions who show symptoms of the virus, commonly known as swine flu, should be treated immediately rather than waiting for the virus to be confirmed in a laboratory test, said Dr. Anne Schuchat, director of CDC's National Center for Immunization & Respiratory Diseases. "We don't want to wait for test results to become available" before starting treatment, she said. The drugs are most effective if treatment is begun within 48 hours after the onset of an infection.
In guidelines issued this spring, the agency had suggested that the drug could be used for close contacts of flu victims to prevent their infection. But the virus has now become so common, Schuchat said, that the drugs should be reserved for those most seriously ill.
Officials are afraid that overuse of the drugs will lead to widespread resistance to them by the virus. Virtually all the circulating strains of seasonal flu are already resistant to Tamiflu. But so far, only 13 cases of swine flu resistance to the drug have been spotted, said officials at the drug's manufacturer, Roche, on Monday.
-- Thomas H. Maugh II