Some types of allergy medications include antihistamines, decongestants, steroids, bronchodilators and mast cell stabilizers, according to WebMD. Combination allergy drugs contain multiple medications to treat more than one allergy symptom.
Allergies occur when a harmless substance triggers the body's immune response sending a signal to mast cells to release histamine, states WebMD. Antihistamines work by keeping the histamine from bonding to receptors and causing allergy symptoms. Commonly used antihistamines include Benadryl, Allegra and Claritin. Mast cell stabilizers work in a similar manner by preventing the release of histamine. Patients take the drugs before being exposed to an allergen to avoid symptoms.
Decongestants, steroids and bronchodilators work by treating allergy symptoms, reports WebMD. Decongestants shrink nasal tissue to reduce stuffiness. Steroids reduce inflammation, also reducing stuffiness and congestion. Steroid inhalers directly decrease inflammation of the airways, and steroid creams reduce skin rashes brought on by allergies. Flonase and Nasonex are common steroid allergy medications.
Bronchodilators are powerful allergy medications for patients with asthma, maintains WebMD. Quick-acting bronchodilators provide immediate relief during asthma attacks while long-acting bronchodilators provide up to 12 hours of relief. Bronchodilators are available only by prescription, and are administered with an inhaler or a nebulizer. They work by relaxing the muscles around the airways to allow patients to breathe more easily.