As far as I am aware you cam take the short acting older style antihistimines like polaramine and phenergan. Just not the new one a day type!! HTH!! Good luck, I get terrible hayfever and I am BF so am finding it sooo hard!!! If I need to i take phenergan at night when DS has gone to bed for the night, then I know it will not be in my milk when he has a feed in the morning!!