I have dealt with allergies in recent weeks. I've switched from Zyrtec to Allegra and both have stopped working. Yesterday I made contact with my internist and his suggestion was to try Mucinex twice daily. The pharmacist suggested that I use Mucinex in addition to the Allegra. After using both last night I felt groggy and very dry. I did not rest well last night. Today I have had lots of drainage. Do I take the Allegra at dinner with the Mucinex or just rely on Mucinex?