In this study, we detected a novel influenza virus A (H3N2) with Q136K mutation in NA and S31N mutation in M2, which demonstrated reduced susceptibility to both zanamivir and
amantadine but remained susceptible to oseltamivir.
Negative studies include a retrospective cohort study of 123 medically stable subjects with severe TBI in coma for more than 1 week, 28 of whom had received 100 to 200 mg of
amantadine twice daily [29].
However, 26.4% of PCPs also prescribed
amantadine or rimantadine.
While primary resistance to
amantadine is uncommon (< 1 - 2.5%) it has been found to be present in some viral isolates from avian, including H5N1, and swine origins.
Amantadine has been used as an antiparkinsonian drug since 1969.
Investigators at the Centers for Disease Control and Prevention detected an "alarmingly high" resistance rate of 92% to
amantadine and rimantadine in an analysis of 209 influenza A(H3N2) isolates from patients in 26 states from Oct.
In June, news reports stated that China's agricultural ministry has encouraged farmers to use
amantadine on flu-infected poultry.
Observational studies strongly suggest that
amantadine, rimantadine, and oseltamivir are all effective in reducing spread of influenza during outbreaks in nursing homes (Table).
The World Health Organisation says this year's strain is resistant to cheaper anti- viral drugs
amantadine and rimantadine.
Medications should be tapered in the order of those with the highest risk-to-benefit ratio: Anticholinergics should be tapered first, followed by selegiline,
amantadine, dopamine agonists, and catechol 0-methyltransferase inhibitors.
Now the appraisal committee will look at a new drug, Tamiflu, which is in the process of being licensed in Europe, and a new formulation of an older drug called
amantadine.
Rimantadine and
amantadine have been approved for use by adults and children who are 1 year of age and older.