Antihistamines relieve redness, inflammation, itchiness, and watery eyes. Most antihistamines also have a sedating effect - they make you sleepy. Non-sedating ones are available, most by prescription. A dry mouth is also a common side effect. Ophthalmic solutions can relieve red, irritated eyes.
Decongestants reduce nasal congestion by constricting blood vessels.
More medication only makes the congestion worse. Discuss this side effect with your physician to understand how to limit the amount of medication you use. Bronchodilators widen the bronchial tubes in the lungs. They are used to decreased allergy symptoms such as coughing, wheezing and shortness of breath. Agitation is a common side effect.