Don’t suffer needlessly from springtime allergy symptoms. Taken once or twice daily, over-the-counter (OTC) products that contain the active ingredient loratadine (Claritin) or cetirizine (Zyrtec) help treat runny nose, sneezing, and itchy and watery eyes. These drugs, which may be used in combination with OTC pseudoephedrine (Sudafed) to relieve congestion, sometimes cause a dry mouth. Diphenhydramine (Benadryl) is another effective option for allergy relief. The OTC product is taken every eight hours and may cause drowsiness.