Many. Allegra, (fexofenadine) or Fexofenadine, have similar side effects profile compared to other newer generation of antihistamine medications. All antihistamine medications also has anticholinergic effects, which can contribute to dizziness, sedation, urinary retention, diarrhea, muscle cramp, gastrointestinal discomfort, menstrual cramp which are related to the anticholinergic effects of the medication.
Allegra (fexofenadine) It can make you dry, the D version can raise your blood pressure and make you feel anxious and in men with enlarged prostrates can make it hard to urinate. Best time to take is between 4 to 6 pm as most things bloom at night.