According to one of my text books (I'm a pharmacy technician intern) fexofenadine, brand name Allegra, the highlights and lowlights of fexofenadine are as follows:
1. not indicated for people with kidney disease
2. azole antifungals may increase the effects of fexofenadine.
3. people who have overdosed need to be administered ipecac.
4. do not combine with alcohol or other nervous system depressants.
4a. use extra caution while doing anything that requires concentration