Antihistamine ED

Has anyone else had a problem getting an erection after using an antihistamine like Claritin or Allegra or Benadryl. My girlfriend has a cat that Iā€™m allergic to so I take an antihistamine before I go to her place, but the times where I do take one I have a problem keeping an erection which is probably also do to psychological issues. However, the times where I have not taken it right before I went to her house I have been able to get and keep an erection adequately.