Drug Info

Allergy medicine and treatments

Cropped SingleCare logo By | October 7, 2019
Medically reviewed by Anis Rehman, MD

What are allergies? | Allergy testing | Allergy treatment options | Allergy medicine | Best allergy medicine | Side effects of allergy medicine | Natural remedies for allergies | FAQResources

Allergies are one of the most common conditions in the world, with the prevalence of allergic diseases rising dramatically over the last 50 years. Sensitization to allergens in the U.S. is approaching 40%-50% among school children alone. In this guide, we’ll explain to you how allergies are tested and diagnosed. First, we’ll compare popular allergy medicine, discuss the side effects, and finally present some natural alternatives to allergy treatment.

What are allergies?

In simple terms, allergies are the body’s overreaction to a foreign substance (an allergen). Some of the most common allergens are certain foods, animal hair (dander), pollen from plants like ragweed, and dust mites.

Depending on the allergen, people with allergies usually experience symptoms such as sneezing, itchy eyes or watery eyes, rashes or hives, asthma, and a runny nose. Fortunately, there are many treatment options available. Both over-the-counter (OTC) and prescription allergy medicines can help alleviate symptoms and reduce allergen sensitivity.

How are allergies diagnosed?

When you’re allergic to a substance, like ragweed pollen, for example, you may notice symptoms like watery eyes and a runny nose. Tracking these symptoms when you come into contact with different allergens can help your doctor diagnose your specific allergy. Your primary care doctor may refer you to a specialist called an allergist or immunologist for tests. Allergists are specifically trained to diagnose, treat, and manage allergies.

Questions to ask your doctor or specialist about possibly having allergies:

  • Do I need any tests? Which ones?
  • What are my treatment options?
  • What is the best allergy medicine for me?
  • Will I have the allergies forever, or will they go away?

Questions your doctor may ask to make an accurate diagnosis and develop a treatment plan:

  • What are your symptoms?
  • When did the symptoms start?
  • Does anything trigger your symptoms?
  • Does anything help alleviate your symptoms?
  • Do you have any other medical conditions or take medication?

Once your allergist or immunologist has a thorough understanding of your medical history and symptoms, they may order some tests. Many allergies can be diagnosed through simple skin or blood tests. They should always be done under the care of a specialist, as there is the risk that allergy symptoms may occur during the test.

It’s important to note that these tests alone won’t diagnose any allergies. Their results, combined with your medical history will help your doctor form a diagnosis.

Allergy skin tests

Skin tests are generally more affordable than allergy blood tests. Plus, they give results very quickly. Skin tests can sometimes be affected by other medicines, so make sure to tell your doctor about any medication you’re taking including prescription drugs, over-the-counter products, and supplements.

An allergy skin test is usually performed on the back of the forearm. The doctor will prick a small amount of the suspected allergen onto the surface of the skin. Your doctor may test several allergens at the same time.

If you are allergic to one of the allergens, your skin will show signs of redness and swelling at the test spot.

Another skin test your doctor may perform is to inject small amounts of a suspected allergen into the skin, rather than a drop on the surface, and monitor for any reaction.

Allergic reactions will often appear within 20 minutes, but they can sometimes be delayed for a few hours. If this is the case, you must report the delayed reaction to your doctor.

Skin testing is an effective, efficient, usually pain-free way for you to find out if you have any allergies. In one appointment you can meet with your allergist, test suspected allergens, get your results, and determine the best allergy treatment for you.

Allergy blood tests

There are three reasons why an allergist or immunologist may use blood tests rather than skin tests for your suspected allergies.

  1. You’re taking medications that will interfere with a skin test.
  2. You have a preexisting skin condition such as eczema or psoriasis.
  3. The allergen being tested could result in a large, severe positive reaction.

Unlike skin tests, you will need to wait a few days for the lab results of your blood tests.

Both skin and blood tests are useful and effective for testing allergies to some medicines, mold, food, pollen, insect stings, dust mites, and animal dander.

Allergy treatment options

After you’ve been diagnosed with an allergy, your doctor will suggest the most appropriate treatment plan for you. Although allergies cannot be cured entirely, there are several ways allergic reactions can be treated and prevented. Your sensitivity can also be significantly reduced, depending on what it is you’re specifically allergic to.

These are the three common ways to treat and avoid allergic reactions. Your doctor may recommend a combination of all three:

1. Avoid allergens

Although not always easy or practical, one of the most effective ways to manage allergies is to avoid exposure to the allergen. For example, if you have food allergies you may become more careful about what you eat. If you have hay fever (also called allergic rhinitis) it may be best to shut the windows and stay indoors and away from grass when the pollen count is high. Allergy season could last nearly all year depending on where you live.

2. Medication

For many mild allergies, you can purchase the appropriate medication over the counter at your local pharmacy. For more severe allergies, your doctor may provide you with prescription medication. The most common types of allergy medications include:

  • Antihistamines
  • Decongestants
  • Steroids
  • Lotions and creams

3. Immunotherapy

Immunotherapy, also known as desensitization, is a treatment option reserved for people who suffer certain severe and persistent allergies. People who try immunotherapy have usually tried other treatment options without success. Under the supervision of a doctor, patients are given small doses of the allergen over time to help their bodies get used to it.

Allergy medicine

There are a number of medications available to help with allergies, both over-the-counter and prescription. They fall into a few different groups, each working slightly differently to treat allergies.


Oral antihistamines are the most popular class of drugs used to treat allergy symptoms. So how do they work? When people experience an allergic reaction, it’s because their immune system is triggered by an allergen (pollen, for example). This means that the immune system begins releasing chemicals called histamines. Histamines latch on the blood vessels and receptors, leading to uncomfortable allergy symptoms like itching and swelling.

As the name suggests, antihistamines work by blocking the release of histamines, therefore preventing them from causing irritation and allergic responses.

The main side effect of antihistamines is drowsiness, however, there are now some newer over-the-counter and prescription antihistamines available that are non-sedating.  It’s best to avoid alcohol when taking antihistamines as it can exacerbate drowsiness.

Popular over-the-counter antihistamines brand names include Benadryl (diphenhydramine), Zyrtec (cetirizine), Allegra (fexofenadine), Claritin, Dimetapp (brompheniramine), Xyzal (levocetirizine), and Clarinex (desloratadine).

RELATED: Allegra vs Zyrtec: Main Differences and Similarities


Decongestants are often used in conjunction with antihistamines. Some of the most common allergy symptoms are nasal congestion or runny nose, and red eyes. This is because allergens can cause the tissues in your nose and blood vessels in your eyes to swell. A decongestant works by reducing the swelling of this tissue, therefore alleviating the symptoms and irritation.

They are available as tablets, eye drops, nasal allergy spray, and liquid. However, both eye drops and nasal spray decongestants should only be taken a few days at a time as their long term use can cause symptoms to worsen.

Some of the most popular over-the-counter decongestants are:

  • Sudafed (pseudoephedrine)
  • Afrin and Neo-Synephrine nasal sprays

Potential side effects of decongestants include increased blood pressure and insomnia.

Combination drugs

These medicines combine both antihistamines and decongestants to treat multiple symptoms at once. Both over-the-counter and prescription allergy medicines are available.

Well-known over-the-counter combination allergy medicines include Benadryl Allergy and Sinus (diphenhydramine and pseudoephedrine), Claritin-D (loratadine and pseudoephedrine), Allegra-D (fexofenadine and pseudoephedrine), and Zyrtec-D (cetirizine and pseudoephedrine).


Steroids, also known as corticosteroids, can reduce inflammation caused by allergic reactions. This helps minimize symptoms such as sneezing, itchy and runny nose, and nasal decongestion.

Steroids are extremely effective in treating allergies, however as they need to be taken daily and they’re best suited to people who have seasonal allergies and on-going, year-round allergies.

Nasal steroids including Qvar, Qnasl, Alvesco, and Nasonex are prescription allergy medicines.

There are also over-the-counter options, including Rhinocort Allergy (budesonide), Flonase Allergy Relief (fluticasone), and Nasacort Allergy 24hr (triamcinolone).

Compared to antihistamines and decongestants, there are generally more side effects associated with steroid use. Some side effects are fluid retention and weight gain, high blood pressure, mood and memory changes, diabetes, and osteoporosis (brittle bones). Long-term steroids may also cause heart disease, abnormal heart rhythm, thinning of the skin, cataract and eye swelling, adrenal insufficiency, and decrease immunity (capacity to fight infections).

What is the best allergy medicine?

As with most medications and treatments, the best allergy medicine for one person may not be the right option for someone else. The right medication for you will be determined by your doctor, taking into consideration your medical condition, and medical history. Your physician will also consider any other medications you may be taking as there is the possibility they could interact with some allergy medications. Your doctor will also be able to monitor your progress and response to treatment and make any changes accordingly.

These are the most commonly recommended allergy medications:

Drug Name Drug Class Administration Route Standard Dosage How It Works Most Common Side Effects
Benadryl (diphenhydramine) Antihistamine Oral 25 mg capsule Blocks the release of histamines Drowsiness


Reduced coordination

Zyrtec (cetirizine) Antihistamine Oral 5 – 10 mg tablet Blocks the release of histamines Fatigue

Dry mouth


Allegra (fexofenadine) Antihistamine Oral 60 – 180 mg tablet Blocks the release of histamines Nausea





Claritin (loratadine) Antihistamine Oral 10 mg tablet Blocks the release of histamines Headache


Stomach pain

Dry mouth

Sudafed (pseudoephedrine) Decongestant Oral 30 mg tablet Reduces swelling of irritated tissue Nervousness



Loss of appetite

Irregular heartbeat

Chest pains

Blood pressure issues

Afrin (oxymetazoline) Decongestant Nasal spray 15 ml of 0.05% Reduces swelling of irritated tissue Blurred vision

Fast or irregular heartbeat

Dry nose

Nasal irritation

Claritin-D 12 Hour (loratadine and pseudoephedrine) Combination Oral Loratadine 5 mg

Pseudoephedrine sulfate 120 mg tablet

Blocks histamine release and reduces nasal tissue swelling Dry mouth





Irregular heartbeat

Chest pains

Allegra-D (fexofenadine and pseudoephedrine) Combination Oral 60 – 120 mg tablet Blocks histamine release and reduces nasal tissue swelling Constipation





Muscle pain

Respiratory infections

Rhinocort Allergy (budesonide) Steroid Nasal spray 8.43 ml of 32 mcg/act Reduces allergy-triggered inflammation Nose and throat dryness

Skin rash






Qvar Redihaler (beclometasone dipropionate) Steroid Inhaler 10.6 gm of 80 mcg/act Reduces allergy-triggered inflammation Sore throat

Sinus pain




Dosage is determined by your doctor based on your medical condition, response to treatment, and other factors.

Other possible side effects exist. This is not a complete list.

What are common side effects of allergy medication?

As with most medications, there is a risk of side effects. Although not a complete list of every possible side effect, here are a few of the most common for different allergy drug types:

  • Antihistamines: Dry mouth, drowsiness, dizziness, difficulty urinating or inability to pee
  • Decongestants: Drowsiness, dizziness, constipation, headache, trouble sleeping
  • Steroids: Insomnia, anxiety and restlessness, hypertension

For a full list of potential side effects, it’s best to speak with your healthcare provider. Your physician will also guide you through any possible drug interactions. Look for warnings from the U.S. Food and Drug Administration (FDA) on prescription labels and medication guides before taking the drug.

Can I treat allergies naturally?

Many people also use a combination of natural remedies in addition to taking medications to alleviate and treat allergies.

Popular ways to naturally prevent or reduce the impact of allergy symptoms are:

  • Vitamins and supplements such as vitamin C, bromelain, butterbur, apple cider vinegar, and quercetin may strengthen your immune system and could reduce inflammation caused by allergies.
  • Lifestyle changes could help you avoid allergens altogether. Think: changing your diet, keeping windows closed, and wearing a mask when allergens like ragweed are high.
  • Improve the air quality at home by cleaning with a vacuum that has a HEPA air filter, maintaining your home’s HVAC system, and using a high-efficiency HEPA air cleaner in every room.
  • Inhaling steam can remove irritants from the nasal passage. Hold your head above a bowl of steaming water, then cover your head with a towel to trap the steam.

Frequently asked questions about allergies

Can allergies be cured?

Generally, no. But you can treat and manage symptoms. Some treatments are so effective they can significantly reduce your sensitivity to some allergens.

How long do allergy symptoms last?

It varies, but allergy symptoms usually last as long as you are exposed to the allergen. Often symptoms will disappear soon after exposure to the allergen is over.

Which allergy medicine works the fastest?

It’s widely acknowledged that Zyrtec Allergy is one of the fastest-acting antihistamines, effective within one hour. However, it is also most likely to cause drowsiness and the effects can last up to 24 hours.

What is the best allergy medicine for pollen?

Although antihistamines are commonly used for pollen allergies, it’s best to speak with your doctor. Only a healthcare professional can figure out which medicine is best for your specific medical condition and medical history.

Is Claritin or Zyrtec better? Can I take both?

Both Claritin and Zyrtec are effective allergy medications. If you’re unsure which allergy medicine is best for you, ask a healthcare professional like your pharmacist to compare Zyrtec vs Claritin. Meanwhile, you can learn more about combining allergy medicine here.

How effective is albuterol for treating allergies?

If you experience wheezing or allergy-triggered coughing, albuterol inhalers can be an effective treatment. However, during severe allergic reactions and anaphylaxis, they are no substitute for epinephrine, commonly known as an EpiPen.

How can I treat allergies during pregnancy?

Speak with your doctor before taking allergy medicine while pregnant. Many doctors suggest a home remedy for allergies, like exercise, sleeping in an elevated position, and over-the-counter saline nasal spray.

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