Types of Allergy Medications

Antihistamines

Antihistamines block histamine, which is an inflammatory chemical released by immune cells during an allergic reaction. Blocking histamine may reduce inflammatory symptoms like redness, swelling, watery eyes, runny nose, and hives.

Over-the-counter oral antihistamines include Benadryl, Chlor-Trimeton, Tavist, and Claritin. Claritin, which was a prescription drug until 2002, is less likely to have side effects of drowsiness.

Prescription antihistamines include Allegra and Zyrtec. Zyrtec may cause drowsiness or affect the ability to drive, but Allegra should not.

Astelin is a prescription antihistamine in the form of nasal spray. Prescription antihistamine eyedrops include Emadine, Livostin, and Patanol. You should not wear contact lenses during treatment with antihistamine eyedrops.

Decongestants

Decongestants relieve nasal and sinus congestion caused by allergic rhinitis as well as eye congestion caused by allergic conjunctivitis. Most decongestants are available over-the-counter.

Over-the-counter oral decongestants include Sudafed and Actifed. Many decongestants contain pseudoephedrine, which can be used as an ingredient to manufacture methamphetamine. Since the Combat Methamphetamine Epidemic Act passed in 2005, allergy sufferers must present identification and sign for medicines that contain pseudoephedrine, and pharmacies must keep records of purchases. Some medications, such as prescription drug Claritin-D, combine pseudoephedrine with an antihistamine. People who have high blood pressure should avoid oral decongestants because the increase blood pressure. Oral decongestants may also exacerbate prostate problems in men.

Decongestant nasal sprays include Afrin and Neo-Synephrine. You shouldn't use a decongestant nasal spray for more than two or three days at a time. Visine is an example of decongestant eyedrop.

Corticosteroids

Corticosteroids relieve the itching and swelling that accompany many allergic disorders. Corticosteroids are usually prescription medications, expect for over-the-counter hydrocortisone creams for hives, dermatitis, insect stings, and other skin allergy problems.

Corticosteroid nasal sprays include Rhinocort, Nasonex, Flonse, and Nasacort, and they relieve nasal stuffiness and itching.

Corticosteroid eyedrops include Decadron, Dexair, Eflone, Econopred, and others. They should not be used if you have glaucoma or an eye infection, and they can cause blurred vision as a side effect. You should not wear contact lenses during treatment with corticosteroid eyedrops. Pregnant women may be advised to avoid corticosteroid eyedrops, as they have been shown to cause birth defects in animals.

Sometimes oral corticosteroids such as prednisone are used to treat severe allergy symptoms. Generally, oral corticosteroids are prescribed for only a short period of time because they can have severe side effects such as cataracts, osteoporosis, and muscle weakness. Furthermore, oral and inhaled steroids have been shown to reduce bone density and affect growth in children.

Leukotriene Modifiers

Like histamine, leukotrienes are inflammatory chemicals released by immune cells during an allergic reaction. Leokotriene modifiers block leukotrienes and are used to treat allergic asthma and sometimes hayfever; they are available only by prescription. Examples include Singulair, Zyflo, and Accolate.

Mast Cell Stabilizers

While antihistamines stop histamine from binding to cells, mast cell stabilizers prevent the release of histamine from mast cells, thereby reducing inflammation. Examples include cromolyn sodium nasal sprays and eyedrops as well as other eyedrops like Alomide, Alamast, and Alocril.

Immunotherapy

For severe allergies, your doctor may recommend immunotherapy, or allergy shots. Given over a period of three to five years, allergy shots contain small amounts of the offending allergen. Over time, the body becomes desensitized to the allergen.

Epinephrine

People with life-threatening allergies - such as peanut allergy or stinging insect allergy - may need to carry an injectible dose of epinephrine (adrenalin) at all times in case of anaphylaxis. Anaphylaxis is a severe, multi-system allergic reaction that can lead to death. Epinephrine slows anaphylaxis, and people who carry epinephrine in an auto-injector are taught how to administer the drug to themselves.