I got prescribed mecklizine, what exactly does it do? and can i take it with my daily allegra (fexofenadine)?

Treats Dizziness: Meclizine usually is recommended to treat vertigo, dizziness, or nausea. It can be taken with your allegra (fexofenadine). Meclizine works to reduce diziness by effecting the inner ear, but it is also a cousin of the antihistamines.

1st gen antihistamin: Meclizine is an antihistamine, reduces body's response to allergic triggers; causes mild sedation in most; suppresses messages from inner ear so reduces dizziness (/vertigo) and motion sickness symptoms. If taking regularly through day, might not need Alegra while on it, but if intermittent or allergy symptoms break through, likely OK to take both for a few days.

Meclizine: Meclizine is an antihistamine that reduces the effects of natural chemical histamine in the body. Meclizine is used to treat or preventnausea, vomiting, and dizziness caused by motion sickness. It is also used to treat symptoms of vertigo (dizziness or spinning sensation) caused by disease that affects your inner ear. Next time ask your doctor what you are being prescribed before taking it.