With more than 50 million Americans suffering from some type of allergy, according to Dr. Arthur Schoenstadt, allergy medications make up a high proportion of both prescription and over-the-counter drug sales. It's not only possible but sometimes necessary to take more than one type of allergy medicine at a time, since different categories of allergy medicines accomplish different purposes. However, you should never mix medications without your doctor's approval, even over-the-counter varieties. Taking two medications with different names but similar effects increases your chance of developing serious side effects.
Allergy medications fall into several different classifications. Some medications prevent allergy attacks; you may typically take these medications daily. Others treat acute allergy symptoms; you may take these when you experience allergy symptoms. Some medications, like allergy shots, can permanently decrease your sensitivity to allergens. Allergy medications may come in oral or inhalant form. If you have a severe allergy attack, called anaphylaxis, injected epinephrine or adrenaline can reduce the release of histamine, which causes many of the severe allergy side effects such as swelling.
Allergy drugs accomplish specific purposes. Since they work on different symptoms, taking several allergy medicines together may reduce symptoms more quickly. Decongestants taken orally or as nasal or eye drops can decrease sinus or nasal congestion as well as relieve the red eyes that often occur with allergic reactions. Use drops only as directed on the bottle. Antihistamines, taken orally or as nasal sprays, reduce histamine production, which reduces symptoms. Corticosteroids, generally available only via prescription in inhaled, oral or drop form, reduce inflammation. Leukotriene modifiers reduce leukotrienes, another chemical cause of an allergic reaction.
Most allergy medications have side effects, with drowsiness the most common reported for antihistamines, although dry mouth and nausea are among other possibilities. Decongestants can also have central nervous system effects, including dizziness, difficulty sleeping, high blood pressure, anxiety, rapid heartbeat and restlessness. Rarely, decongestant eye drops can cause a rise in eye pressure called glaucoma. Corticosteroids taken orally have a long list of long-term effects such as skin thinning, mood swings, weight gain, fluid retention and bone loss. Take corticosteroids only under your doctor's supervision.
Some drugs that come in both prescription and over-the-counter version combine antihistamines and decongestants, which can decrease the number of pills you have to take. If you do take combination medications, make sure you're not taking other medications that have the same purpose. Ask your doctor to check your medication list for possible duplications.
Make sure you don't have older decongestants containing phenylpropanolamine in your medicine chest. The U.S. Food and Drug Administration banned PPA in 2000 because studies showed it increases the risk of hemorrhagic stroke, particularly in women age 18 to 49, the Cleveland Clinic warns.