The influenza virus may be developing resistance to a drug recently approved for the prevention and treatment of the disease, say researchers from Japan.
They report their results in the April 2001 issue of the Journal of Clinical Microbiology.The drug, known as amantadine, has only recently been approved for the prevention and treatment of influenza in Japan, but had been widely used for years to treat symptoms of Parkinson's disease and other neuropsychiatric disorders.
The researchers studied Japanese patients on long-term amantadine therapy for these disorders who developed influenza. Two of the influenza viruses isolated were amantadine-resistant.
"This is the first report of isolation of amantadine-resistant viruses from patients receiving long-term amantadine treatment for Parkinsonism, neuropsychiatric disorders and apathy due to cerebral infarction," say the researchers. "Our results indicate that the amantadine-resistant viruses may naturally circulate and emerge from patients receiving long-term treatment with amantadine."
In the United States, amantadine is also approved for treatment of Parkinson's and influenza. The drug is currently being tested as a treatment for chronic hepatitis C.
(Reference: J. Iwahashi, K. Tsuji, T. Ishibashi, J. Kajiwara, Y. Imamura, R. Mori, K. Hara, T Kashiwagi, Y. Ohtsu, N. Hamada, H. Maeda, M. Toyoda, and T. Toyoda. 2001. Isolation of amantadine-resistant influenza A viruses (H3N2) from patients following administration of amantadine in Japan. Journal of Clinical Microbiology, 39: 1652-1653.)
11-Apr-2001
