Infections in pregnancy also raise particular concerns about whether or not to use drugs in pregnancy (that is, antibiotics or antivirals) to treat them. For example, pregnant women who contract H1N1 influenza infection are recommended to receive antiviral therapy with either oseltamivir (which is the preferred medication) or zanamivir.[8] Both amantadine and rimantadine have been found to be teratogenic and embryotoxic when given at high doses in animal studies.[8]