There are four different antiviral drugs that are licensed for use in the US for the treatment of influenza: amantadine, rimantadine, oseltamivir and zanamivir. While most swine influenza viruses have been susceptible to all four drugs, the most recent H1N1 influenza viruses isolated from humans are resistant to amantadine and rimantadine.
Reference: Facts come from the cdc.gov website on virus h1n1flu (swine flu)