Seasonal allergies can be treated with over-the-counter (OTC) medications including antihistamines to reduce allergy symptoms and decongestants to relieve nasal congestion. Proper dosage and administration of OTC medications is important, such as taking tablets once, twice or three times daily and using sprays, drops, or creams topically as directed. Medications can be administered orally, topically, via inhaler, or spray depending on the specific drug and condition being treated.