The CDC has issued recommendations for the use of anti-viral medications in patients with influenza this year, due to the high resistance of Influenza A (H1N1) to oseltamivir. Of the few Influenza A (H1N1) strains tested this year, 98% were resistant to oseltamivir (but all were susceptible to zanamivir, amantadine, and rimantadine) (CDC site). They recommend avoiding oseltamivir in patients with Influenza A (unless local surveillance suggests the dominant Influenza A strain is H3N2, and not H1N1). Oseltamivir can still be used for Influenza A (H3N2) or Influenza B. Amantadine and rimantadine have no activity against Influenza B, and are generally ineffective against Influenza A (H3N2). In summary, Influenza A (H1N1) can be treated with zanamivir, amantadine or rimantadine; Influenza A (H3N2) can be treated with zanamivir or oseltamivir; Influenza B can be treated with zanamivir or oseltamivir.
Dr. Scheurer is a clinical hospitalist and the Medical Director of Quality and Safety at the Medical University of South Carolina in Charleston, South Carolina, and is Assistant Professor of Medicine. She is a graduate of the University of Tennessee College of Medicine, completed her residency at Duke University, and completed her Masters in Clinical Research at the Medical University of South Carolina. She also serves as the Web Editor and Physician Advisor for the Society of Hospital Medicine.