Medicines to treat allergy symptoms: prescription and over-the-counter medicines


In general, there is no cure for allergies, but there are several types of medications available – over the counter and prescription – to help relieve and treat bothersome symptoms like stuffy nose and runny nose. These allergy medications include antihistamines, decongestants, combination drugs, corticosteroids, and others.

Immunotherapy in the form of allergy shots or pills under the tongue, which gradually increases your ability to tolerate allergens, is also available.


Antihistamines have been used for years to treat allergy symptoms. They can be taken as tablets, liquid, nasal spray, or eye drops. Over-the-counter (OTC) antihistamine eye drops can relieve red itchy eyes, while nasal sprays can be used to treat symptoms of seasonal or permanent allergies.

Examples of antihistamines are:

  • Over the counter:Cetirizine (Zyrtec), fexofenadine (Allegra), levocetirizine (Xyzal) and loratadine (Alavert, Claritin) are taken by mouth. Brompheniramine (Dimetapp allergy, Nasahist B), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist), and diphenhydramine (Benadryl) can make you drowsy. Ketotifen (Zaditor) and the ophthalmic combination of naphazoline and pheniramine (OcuHist) are eye drops.
  • Prescription: Desloratadine (Clarinex) is a medicine taken by mouth. Nasal azelastine (Astelin) is a nasal spray. Eye drops include azelastine ophthalmic (Optivar), epinastine ophthalmic (Elestat), and olopatadine ophthalmic (Patanol).

How do antihistamines work?

When you are exposed to an allergen – for example, ragweed pollen – it triggers your immune system. People with allergies have an exaggerated immune response. Cells of the immune system called “mast cells” release a substance called histamine, which attaches to receptors in the blood vessels, causing them to enlarge. Histamine also binds to other receptors, causing redness, swelling, itching, and changes in secretions. By blocking histamine and preventing it from binding to receptors, antihistamines prevent these symptoms.

What are the side effects of antihistamines?

Many older over-the-counter antihistamines can cause drowsiness. Newer antihistamines that don’t make you drowsy are available over the counter and by prescription.


Decongestants relieve congestion and are often prescribed along with antihistamines for allergies. They can come in the form of nasal sprays, eye drops, fluids, and pills.

Nasal spray decongestants and eye drops should only be used for a few days at a time, as long-term use may make symptoms worse. It is safe to take pills and liquid decongestants for longer.

Here are some examples of over-the-counter decongestants:

How do decongestants work?

During an allergic reaction, the tissues in your nose may swell in response to contact with the allergen. This swelling produces fluid and mucus. Blood vessels in the eyes may also swell, causing redness. Decongestants work by narrowing nasal tissues and swollen blood vessels, relieving symptoms of nasal swelling, congestion, mucus secretion, and redness.

What are the side effects of decongestants?

Decongestants can increase blood pressure, so they are generally not recommended for people with blood pressure issues or glaucoma. They can also cause insomnia or irritability and restrict urine flow.

Combined allergy medications

Some allergy medications contain both an antihistamine and a decongestant to relieve multiple allergic symptoms. Other drugs have multiple effects in addition to blocking the effects of histamine, such as preventing mast cells from releasing other chemicals that cause allergies.

Here are some examples of combination allergy medications:

Anticholinergic nasal sprays

The drug Ipratropium bromide (Atrovent) can reduce a runny nose. When sprayed into each nostril, it decreases the mucus from the glands lining the nasal passages.

What are the side effects of anticholinergic nasal sprays?

They can cause a very dry nose, leading to nosebleeds or irritation. Other side effects include headaches, a stuffy nose, upset stomach, and sore throat.


Steroids, known medically as corticosteroids, can reduce inflammation associated with allergies. They prevent and treat nasal congestion, sneezing and itchy runny nose due to seasonal or permanent allergies. They can also reduce inflammation and swelling caused by other types of allergic reactions.

Systemic steroids are available in various forms: as tablets or liquids for severe allergies or asthma, topical inhalers for asthma, topical nasal sprays for seasonal or permanent allergies, topical creams for skin allergies or topical eye drops for allergic conjunctivitis. In addition to steroid drugs, your doctor may decide to prescribe other types of drugs to help fight your allergic symptoms.

Steroids are very effective allergy medications, but they need to be taken regularly, often daily, to be of benefit, even when you are not having allergy symptoms. Additionally, it may take 1 to 2 weeks before the full effect of the drug can be felt.

Some steroids include:

  • Prescription nasal steroids: beclomethasone (Beconase, Qnasl, Qvar), ciclesonide (Alvesco, Omnaris, Zetonna), fluticasone furoate (Veramyst) and mometasone (Nasonex)
  • Over-the-counter nasal steroids: budesonide (Rhinocort Allergy), fluticasone (Flonase Allergy Relief) and triamcinolone (Nasacort Allergy 24HR)
  • Eye drops: dexamethasone ophthalmic (Maxidex) and loteprednol ophthalmic (Alrex)
  • Oral steroids:prednisone (Deltasone)

What are the side effects of steroids?

Steroids have many potential side effects, especially when taken for a long time.

Side effects of systemic steroids with short term use include:

  • Weight gain
  • Water retention
  • Arterial hypertension

Side effects with long term use include:

  • Suppression of growth
  • Diabetes
  • Cataracts of the eyes
  • Slimming osteoporosis
  • Muscular weakness

Side effects of inhaled steroids may include coughing, hoarseness, or fungal infections in the mouth.

Mast cell stabilizers

Mast cell stabilizers treat mild to moderate inflammation.

Mast cell stabilizers are available as eye drops for allergic conjunctivitis and nasal sprays for symptoms of nasal allergy. As with many medications, it may take several weeks for the full effects to be felt.

Here are some examples of mast cell stabilizers:

How do mast cell stabilizers work?

Mast cell stabilizers prevent the release of histamine from mast cells (cells that make and store histamine). Some of these drugs also have strong anti-inflammatory effects, but they are usually not as effective as steroids.

What are the side effects of mast cell stabilizers?

Sometimes throat irritation, coughing, or rash occurs. Mast cell stabilizers in the form of eye drops can cause burning, stinging, or blurred vision.

Leukotriene modifiers

Leukotriene modifiers treat asthma and nasal allergy symptoms. They can be prescribed with other medications.

These medications are only available with a doctor’s prescription and come as pills, chewable tablets, and oral granules.

The only leukotriene modifier approved by the FDA is montelukast (Singulair).

How do leukotriene modifiers work?

Leukotriene modifiers block the effects of leukotrienes, chemicals produced in the body in response to an allergic reaction.

What are the side effects of leukotriene modifiers?

Side effects of these drugs are rare but can include:

  • Stomach ache or stomach ache
  • Stomach pains
  • Fever
  • Congested nose
  • Cough
  • Eruption
  • Headache
  • Irritability

Other over-the-counter products

There are some simple over-the-counter products that can help relieve allergy symptoms. They understand:

  • A salt water solution, or saline solution, is available as a nasal spray to relieve mild congestion, loosen mucus, and prevent scabs from forming. These sprays do not contain any medication.
  • Artificial tears, which also do not contain medication, are available to treat itchy, watery eyes, and red eyes.


Immunotherapy may be one of the most effective forms of treatment if you have allergies for more than 3 months of the year. Allergy shots expose you to gradually increasing levels of the offending allergen to help your immune system build tolerance.

The FDA has approved several immunotherapy tablets under the tongue that can be taken at home. Prescription tablets, called Grastek, Oralair, and Ragwitek, treat hay fever and work the same way as injections. The goal is to increase a patient’s tolerance to allergy triggers. Odactra is a medicine under the tongue that can relieve the symptoms of house dust mite allergies. Palforzia treats peanut allergy.


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