For a runny nose you need an antihistamine -- something that will dry you you like Claritin, Bendryl, CTM, etc. You can buy these over the counter and talk to a pharmacist if you have questions.
If you are congested you need something like Sudafed. Not Sudafed PE, that stuff sucks. My drug of choice for allergies, cold, cough stuff is Claritin D. It has an antihistamine and Sudafed in it. Get he 24 hour kind. Works great.
-mark