Allergy medications are available as pills, liquids, inhalers, nasal sprays, eyedrops, skin creams and shots (injections). Some allergy medications are available over-the-counter, while others are available by prescription only. Here's a summary of the various types of allergy medications and why they're used.
Antihistamines block histamine, a symptom-causing chemical released by your immune system during an allergic reaction.
Pills and liquids
Oral antihistamines, available as over-the-counter and prescription drugs, ease runny nose, itchy or watery eyes, hives, swelling, and other signs or symptoms of allergies. Because some of these drugs can cause drowsiness and fatigue, they shouldn't be taken when driving or doing other potentially dangerous activities.
Antihistamines that tend to cause drowsiness include:
- Diphenhydramine (Benadryl)
These antihistamines are much less likely to cause drowsiness:
- Cetirizine (Zyrtec)
- Desloratadine (Clarinex)
- Fexofenadine (Allegra)
- Levocetirizine (Xyzal)
- Loratadine (Alavert, Claritin)
Antihistamine nasal sprays help relieve sneezing, itchy or runny nose, sinus congestion, and postnasal drip. Side effects of antihistamine nasal sprays may include a bitter taste, drowsiness or fatigue. Prescription antihistamine nasal sprays include:
- Azelastine (Astelin, Astepro)
- Olopatadine (Patanase)
Antihistamine eyedrops, available as over-the-counter or prescription medicines, can ease itchy, red, swollen eyes. These drops may have a combination of antihistamines and other medicines.
Side effects may include headache and dry eyes. If antihistamine drops sting or burn, try keeping them in the refrigerator or using refrigerated artificial-tear drops before you use the medicated drops. Examples include:
- Azelastine (Optivar)
- Emedastine (Emadine)
- Ketotifen (Alaway, Zaditor)
- Olopatadine (Pataday, Patanol)
- Pheniramine (Visine-A, Opcon-A, others)
Decongestants are used for quick, temporary relief of nasal and sinus congestion. They can cause insomnia, headache, increased blood pressure and irritability. They are not recommended for women who are pregnant or for people with high blood pressure, cardiovascular disease, glaucoma or hyperthyroidism.
Pills and liquids
Oral decongestants relieve nasal and sinus congestion caused by hay fever (allergic rhinitis). Many decongestants, such as pseudoephedrine (Sudafed, Afrinol, others), are available as over-the-counter drugs.
A number of oral allergy medications contain a decongestant combined with an antihistamine. Examples include:
- Cetirizine and pseudoephedrine (Zyrtec-D)
- Desloratadine and pseudoephedrine (Clarinex-D)
- Fexofenadine and pseudoephedrine (Allegra-D)
- Loratadine and pseudoephedrine (Claritin-D)
Nasal sprays and drops
Nasal decongestant sprays and drops relieve nasal and sinus congestion if they are used for a short period of time. Repeated use of these drugs for more than three consecutive days may result in a cycle of recurring or worsening congestion. Examples include:
- Oxymetazoline (Afrin, Dristan, others)
- Tetrahydrozoline (Tyzine)
Corticosteroids relieve symptoms by suppressing allergy-related inflammation. Most of these medications require a prescription.
Corticosteroid sprays prevent and relieve stuffiness, sneezing and runny nose. Side effects can include an unpleasant smell or taste, nasal irritation and nosebleeds. Examples include:
- Budesonide (Rhinocort Aqua)
- Fluticasone furoate (Veramyst)
- Fluticasone propionate (Flonase)
- Mometasone (Nasonex)
- Triamcinolone (Nasacort Allergy 24 Hour)
Inhaled corticosteroids are often used every day as part of treatment for asthma caused or complicated by reactions to airborne allergy triggers (allergens). Side effects are generally minor and can include mouth and throat irritation and oral yeast infections. Some inhalers combine corticosteroids with other asthma medications. Prescription inhalers include:
- Beclomethasone (Qvar)
- Budesonide (Pulmicort Flexhaler)
- Ciclesonide (Alvesco)
- Fluticasone (Advair Diskus, Flovent Diskus, others)
- Mometasone (Asmanex Twisthaler)
Corticosteroid eyedrops are used to relieve persistent itchy, red or watery eyes when other interventions aren't effective. A physician specializing in eye disorders (ophthalmologist) usually monitors the use of these drops because of the risk of vision impairment, cataracts, glaucoma and infection. Examples include:
- Fluorometholone (Flarex, FML)
- Loteprednol (Alrex, Lotemax)
- Prednisolone (Omnipred, Pred Forte, others)
- Rimexolone (Vexol)
Pills and liquids
Oral corticosteroids are used to treat severe symptoms caused by all types of allergic reactions. Long-term use can cause cataracts, osteoporosis, muscle weakness, stomach ulcers, increased blood sugar (glucose) and delayed growth in children. Oral corticosteroids can also worsen hypertension. Prescription oral corticosteroids include:
- Prednisolone (Flo-Pred, Prelone, others)
- Prednisone (Prednisone Intensol, Rayos)
Corticosteroid creams relieve allergic skin reactions such as itching, redness, scaling or other irritations. Some low-potency corticosteroid creams are available without a prescription, but talk to your doctor before using these drugs for more than a few weeks.
Side effects can include skin discoloration and irritation. Long-term use, especially of stronger prescription corticosteroids, can cause thinning of the skin and disruption of normal hormone levels. Examples include:
- Betamethasone (Dermabet, Diprolene, others)
- Desonide (Desonate, DesOwen)
- Hydrocortisone (Cortaid, MiCort-HC, others)
- Mometasone (Elocon)
Mast cell stabilizers
Mast cell stabilizers block the release of immune system chemicals that contribute to allergic reactions. These drugs are generally safe but usually need to be used for several days to reach full effect. They are usually used when antihistamines are not working or not well-tolerated.
Generic over-the-counter nasal sprays are sold as cromolyn.
Prescription eyedrops include the following:
- Cromolyn (Crolom)
- Lodoxamide (Alomide)
- Pemirolast (Alamast)
- Nedocromil (Alocril)
A leukotriene inhibitor is a prescription medication that blocks symptom-causing chemicals called leukotrienes. This oral medication relieves allergy signs and symptoms including nasal congestion, runny nose and sneezing. Only one type of this drug, montelukast (Singulair), is approved for treating hay fever.
In some people, leukotriene inhibitors may cause psychological symptoms such as irritability, anxiousness, insomnia, hallucinations, aggression, depression, and suicidal thinking or behavior.
Immunotherapy is carefully timed and gradually increased exposure to allergens, particularly those that are difficult to avoid, such as pollens, dust mites and molds. The goal is to train the body's immune system not to react to these allergens. Immunotherapy may be used when other treatments aren't effective or tolerated. It may help prevent the development of asthma in some people.
Immunotherapy may be administered as a series of shots, usually one or two times a week for three to six months. This is followed by a series of less frequent maintenance shots that usually continue for three to five years.
Side effects may include irritation at the injection site and allergy symptoms such as sneezing, congestion or hives. Rarely, allergy shots can cause anaphylaxis, a sudden life-threatening reaction that causes swelling in the throat, difficulty breathing and other signs and symptoms.
Sublingual immunotherapy (SLIT)
With this type of immunotherapy, you place an allergen-based tablet under your tongue (sublingual) and allow it to be absorbed. This daily treatment has been shown to reduce runny nose, congestion, eye irritation and other symptoms associated with hay fever. It also improves asthma symptoms and may prevent the development of asthma. SLIT tablets contain extracts from pollens of different types of grass, including the following:
- Short ragweed (Ragwitek)
- Sweet vernal, orchard, perennial rye, Timothy and Kentucky blue grass (Oralair)
- Timothy grass (Grastek)
Emergency epinephrine shots
Epinephrine shots are used to treat anaphylaxis, a sudden, life-threatening reaction. The drug is administered with a self-injecting syringe and needle device (autoinjector). You may need to carry two autoinjectors and wear an alert bracelet if you're likely to have a severe allergic reaction to a certain food, such as peanuts, or if you're allergic to bee or wasp venom.
A second injection is often needed. Therefore, it's important to call 911 or get immediate emergency medical care.
Your doctor or a member of the clinical staff will train you on how to use an epinephrine autoinjector. It is important to get the type that your doctor prescribed, as the method for injection may be slightly different for each brand. Also, be sure to replace your emergency epinephrine before the expiration date. Examples of these medications include:
Get your doctor's advice
Work with your doctor to choose the most effective allergy medications and avoid problems. Even over-the-counter allergy medications have side effects, and some allergy medications can cause problems when combined with other medications.
It's especially important to talk to your doctor about taking allergy medications in the following circumstances:
- You're pregnant or breast-feeding.
- You have a chronic health condition, such as diabetes, glaucoma, osteoporosis or high blood pressure.
- You're taking any other medications, including herbal supplements.
- You're treating allergies in a child. Children need different doses of medication or different medications than adults.
- You're treating allergies in an older adult. Some allergy medications can cause confusion, urinary symptoms or other side effects in older adults.
- You're already taking an allergy medication that isn't working. Bring the medication with you in its original bottle or package when you see your doctor.
Keep track of what symptoms you experience, when you use your medications and how much you use. This will help your doctor figure out what works best. You may need to try a few different medications to determine which ones are most effective and have the least bothersome side effects for you.