Can you tell me what is the best prescription allergy medicine?

Nasal steroids: As long as you are talking about allergic rhinitis, nasal steroids have shown in studies to provide the greatest amount of relief. As far as cost-effectiveness goes, i would use generic flonase, which is going to be preferred on most plans.

Nasal steriod sprays: Nasal steroid sprays, when used consistently, are the most effective single agent medication. However, for some people, even that is not enough. So they may need multiple medication. One of the most effective combinations is nasal steroid + a nasal antihistamine. They are prescriptions, to talk to your doc. Finally, the most potent treatment safe for long term use are allergy shots.