Anti-viral drugs and influenza

According to the chemical properties and spectrum of activity against influenza viruses, the drugs can be divided into:

• adamantane derivatives - amantadine (not currently recommended for treatment of, and rimantadine
• neuraminidase (NA) inhibitors - zanamivir and oseltamivir (1)

In terms of chemoprophylaxis:

• treatments likely to be beneficial include:
  • oral oseltamivir (prevention of symptoms in influenza A and B)
  • orally inhaled zanamivir (prevention of symptoms in influenza A and B)
• treatments likely to be ineffective or harmful
  • oral amantadine
  • oral rimantadine

In terms of antiviral treatment for cases of influenza:

• treatments likely to be beneficial
  • oral oseltamivir for early treatment of influenza A and B (evidence reveals that there is a reduction in duration of symptoms and incidence of complications)
  • orally inhaled zanamivir for early treatment of influenza A or B (reduction in duration of symptoms and incidence of complications)
• treatments likely to be ineffective or harmful
  • oral amantadine for early treatment of influenza A
  • oral rimantadine for early treatment of influenza A

Reference:

• (1) World Health Organization (WHO). WHO Global Influenza Surveillance Network. Manual for the laboratory diagnosis and virological surveillance of influenza
• (2) National Institute for Health and Clinical Excellence (NICE) 2009. Amantadine, oseltamivir and zanamivir for the treatment of influenza (review of NICE technology appraisal guidance 58)
• (3) BMJ (October 2006). Clinical Evidence - Influenza.
• (4) EBM (2000); 5 (3): 80