Allergy Medications: Your Complete Guide

Allergies can disrupt daily life and even pose health risks. Thankfully, modern medicines like antihistamines and nasal sprays effectively ease symptoms, reduce inflammation, and help you breathe easier.

Knowing what these treatments are for and how they work prevents complications. Whether you're dealing with seasonal allergies, itchy eyes, or preparing for emergencies like anaphylaxis, this guide outlines what to expect from different allergy medications.

Antihistamine Medications

Antihistamines can be helpful medications for treating allergies. They work by blocking histamine, a chemical your body releases during an allergic reaction that causes symptoms like sneezing, runny nose, itching, and watery eyes [*]. Available in various forms — such as pills, nasal sprays, and eye drops — antihistamines give patients flexible options to suit their different needs and preferences.

Antihistamine Nasal sprays

Antihistamine nasal sprays offer quick relief from nasal allergy symptoms like sneezing and congestion. Applied directly into the nose, they target symptoms locally, which helps reduce overall side effects. However, some users might experience a bitter taste, nasal dryness, or irritation.

Common antihistamine nasal sprays include:

• Azelastine (Astelin, Astepro)
• Olopatadine (Patanase)
• Azelastine/Fluticasone antihistamine and steroid combination (Dymista)
  

Antihistamine Oral Tablets & Syrups

Oral antihistamines are available in both tablet and syrup forms. Tablets are convenient and portable, and they are commonly used by adults and older children. Syrups, on the other hand, are ideal for younger children or individuals who have difficulty swallowing pills. They also offer flexibility in dosing.

Another important thing to note is that oral antihistamines offer systemic relief and are available in older first- and newer second-generation formulations.

First-generation antihistamines are effective but can cause drowsiness because they cross the blood-brain barrier [*]. Other side effects include dry mouth, dizziness, and, in some cases, blurred vision or difficulty concentrating.

Examples of older  first-generation antihistamines include:

• Diphenhydramine (Benadryl)
• Chlorpheniramine (Chlor-Trimeton)
• Clemastine (Tavist)
• Hydroxyzine (Vistaril, Atarax)
• Brompheniramine (Dimetapp)

Newer Second-generation antihistamines are less sedating but may still occasionally lead to headaches, dry mouth, or mild gastrointestinal discomfort. They are longer-lasting, which makes them ideal for daytime use.

Common examples of second-generation antihistamines include:

• Loratadine (Claritin)
• Cetirizine (Zyrtec)
• Fexofenadine (Allegra)
• Levocetirizine (Xyzal)
• Desloratadine (Clarinex)
  

Antihistamine Eye Drops

Antihistamine eye drops are specifically formulated to relieve itching, redness, and watering caused by eye allergies (allergic conjunctivitis). They work by blocking histamine — a chemical released during allergic reactions — from affecting the eye tissues, which then provides quick relief from these symptoms.

Common side effects include temporary stinging or burning sensations upon application and dryness or redness in the eyes.

Common options include:

• Ketotifen (Zaditor, Alaway)
• Olopatadine (Pataday, Patanol, Pazeo)
• Azelastine (Optivar)
• Epinastine (Elestat)
• Bepotastine (Bepreve)
  

Decongestant Medications

Decongestants are medications designed to relieve nasal and sinus congestion caused by allergies, colds, or sinus infections. They work by narrowing the blood vessels in the nasal passages to reduce swelling and improve airflow.

It's important to follow the recommended dosage and duration of use for decongestants. Overuse, especially of decongestant nasal sprays, can lead to rebound congestion, where nasal passages become more congested once the medication wears off [*].

Decongestant Nasal Sprays

Over the counter decongestant nasal sprays provide fast-acting, localized relief for nasal congestion. They are effective but should be used for no longer than 3-4 days to avoid rebound congestion.

Common examples of decongestant nasal sprays include:

• Oxymetazoline (Afrin, Dristan)
• Phenylephrine nasal spray (Neo-Synephrine)
• Xylometazoline (Otrivin)
• Naphazoline nasal spray (Privine)
• Tetrahydrozoline nasal spray

It's important to follow the recommended usage instructions and consult with a healthcare provider if your symptoms persist.

Decongestant Oral Tablets

Oral decongestants offer systemic relief and are commonly used for longer-term congestion management or when other symptoms are present.

Although oral decongestants are less likely to cause rebound rhinitis compared to nasal decongestants, the side effects of oral decongestants can still be significant, and some have been taken off the market by the FDA. They should not be used by people with certain health problems, like high blood pressure, heart issues, trouble urinating, or eye problems like glaucoma.

Examples of oral decongestants include:

• Pseudoephedrine (Sudafed)
• Phenylephrine (Sudafed PE)
• Combination products with pseudoephedrine (e.g., Claritin-D, Zyrtec-D, Allegra-D).
• Ephedrine (less common)
• Combination products with phenylephrine (e.g., DayQuil, Mucinex Sinus-Max).
  

Corticosteroid Medications

Corticosteroids are medications that help reduce inflammation and are used for many allergic and inflammatory conditions. They work by reducing swelling, redness, and mucus, which helps to ease symptoms. 

These medications come in different forms, like nasal sprays, creams, or inhalers, depending on the condition being treated and where it affects the body.

Corticosteroid Nasal Sprays

Corticosteroid nasal sprays are commonly prescribed for managing nasal allergy symptoms, including congestion, sneezing, and a runny nose. These sprays act locally in the nasal passages, which minimizes systemic absorption.

Common side effects include nasal dryness, irritation, and occasional nosebleeds. Some individuals may experience a sore throat or mild burning or stinging in the nose.

Examples of corticosteroid nasal sprays include: 

• Fluticasone (Flonase, Veramyst)
• Budesonide (Rhinocort)
• Mometasone (Nasonex)
• Triamcinolone (Nasacort)
• Beclomethasone (Beconase AQ)
  

Corticosteroid Inhalers

Corticosteroid inhalers are a cornerstone treatment for asthma that is caused or worsened by reactions to allergens. They reduce airway inflammation to improve breathing and prevent asthma attacks [*].

Side effects are usually localized to the mouth and throat and may include hoarseness, throat irritation, or a dry mouth. A common issue with inhalers is oral thrush (fungal infection), which can be mitigated by rinsing the mouth after use. Long-term use, especially at high doses, has been studied and may slightly reduce bone density or affect growth in children.

Common corticosteroid inhalers include:

• Fluticasone (Flovent, Arnuity Ellipta)
• Budesonide (Pulmicort)
• Beclomethasone (Qvar RediHaler)
• Mometasone (Asmanex Twisthaler)
• Ciclesonide (Alvesco)
  

Corticosteroid Skin Creams

Topical corticosteroid creams are frequently used to relieve itching, redness, and inflammation associated with conditions like eczema, psoriasis, and dermatitis.

While generally safe, prolonged use may cause skin thinning, stretch marks, or discoloration. Some users may notice a burning or stinging sensation upon application, and there’s a risk of increased hair growth or infection at the treated site, especially with higher-potency formulations.

Examples of topical corticosteroid creams include:

• Hydrocortisone (Cortizone-10)
• Betamethasone (Diprolene, Betnovate)
• Clobetasol (Clobex, Temovate)
• Triamcinolone (Kenalog)
• Mometasone (Elocon)
  

Corticosteroid Oral Tablets

Oral corticosteroids are used for more severe allergic or inflammatory conditions, such as asthma exacerbations, autoimmune diseases, and severe allergic reactions. Because they work systemically, side effects are more widespread and may include weight gain, increased appetite, mood changes, anxiety, or insomnia.

Long-term use can lead to more serious complications, such as high blood pressure, elevated blood sugar levels, osteoporosis, muscle weakness, or adrenal suppression.

Examples of oral corticosteroids include:

• Prednisone
• Methylprednisolone (Medrol)
• Dexamethasone (Decadron)
• Hydrocortisone (Cortef)
• Betamethasone (Celestone)
  

Mast Cell Stabilizers

Mast cell stabilizers are medications that prevent mast cells from releasing histamine and other inflammatory chemicals during an allergic reaction [*]. They are often used for preventing and managing mild to moderate allergy symptoms, particularly when other treatments, such as antihistamines or corticosteroids, are insufficient or not well-tolerated.

These medications are most effective when used regularly, as they work by building up in the system over time. While generally well-tolerated, they can have mild side effects depending on the form used.

Mast Cell Stabilizer Nasal Sprays

Mast cell stabilizer nasal sprays are designed to prevent allergic nasal symptoms, such as sneezing, congestion, and a runny nose. These sprays work locally in the nasal passages and are most effective when used before exposure to allergens.

Common side effects include nasal irritation, sneezing, or a mild burning sensation in the nose. Some individuals may also experience a bitter aftertaste or headaches. These effects are usually mild and resolve on their own.

Examples of mast cell stabilizers include:

• Cromolyn sodium (NasalCrom)
• Cromolyn combination with Ipratropium bromide
• Nedocromil nasal spray
• Ketotifen nasal spray
• Lodoxamide nasal spray
• Olopatidine nasal spray (Patanase)
  

Mast Cell Stabilizer Eye Drops

Mast cell stabilizer eye drops are used to relieve and prevent symptoms of allergic conjunctivitis, such as redness, itching, and watering of the eyes. These drops act locally in the eyes and are particularly useful during allergy seasons or for those frequently exposed to allergens like pollen.

Side effects may include mild stinging or burning upon application, temporary blurred vision, or dryness in the eyes. Some individuals may notice redness in the eyes immediately after use, but this typically subsides quickly.

Examples of mast cell stabilizer eye drops include:

• Cromolyn sodium (Opticrom)
• Nedocromil (Alocril)
• Lodoxamide (Alomide)
• Ketotifen (Zaditor)
• Olopatadine (Patanol, Pataday)
  

Leukotriene Receptor Antagonists

Leukotriene receptor antagonists (LTRAs) are oral medications that block leukotrienes, chemicals involved in inflammation, airway tightening, and mucus production.

They are used to manage chronic asthma and allergic rhinitis, especially when other treatments are insufficient [*]. LTRAs are usually well-tolerated but may cause headaches, stomach pain, or nausea. Rarely, mood changes or irritability may occur.

Examples include:

• Montelukast (Singulair)
• Zafirlukast (Accolate)
• Pranlukast (Ultair)
• Zileuton (Zyflo)
• Ibudilast (Ketas)
  

Immunotherapy

Immunotherapy is a long-term treatment option for allergies that works by gradually desensitizing the immune system to specific allergens. It is particularly beneficial for people with severe allergies who take allergy medications with continued symptoms.

The goal is to reduce the severity of allergic reactions over time. Immunotherapy is available in two main forms: allergy shots and sublingual tablets or drops. While generally safe, side effects may occur depending on the form used.

Allergy Shots

Allergy shots, or subcutaneous immunotherapy (SCIT), involve injecting small, gradually increasing amounts of allergens into the body. This approach builds immunity or tolerance to the allergen over time.

Common side effects include localized redness, swelling, or itching at the injection site. Some individuals may experience mild allergic reactions, such as nasal congestion or sneezing. Rarely, severe reactions like anaphylaxis can occur, requiring immediate medical attention.

Sublingual tablets or Drops

Sublingual immunotherapy (SLIT) involves placing allergen tablets or drops under the tongue daily. This method is a needle-free alternative to allergy shots and is effective, but only for specific allergens.

Common side effects include itching or tingling in the mouth, throat irritation, or mild swelling in the lips or tongue. These effects are typically mild and temporary. Rarely, systemic allergic reactions may occur.

Sample medications for sublingual immunotherapy include:

• Odactra (for dust mite allergies)
• Grastek (for Timothy grass pollen allergies)
• Oralair (for mixed grass pollen allergies, including sweet vernal, orchard, perennial, rye, timothy, and Kentucky blue grasses)
• Ragwitek (for ragweed pollen allergies)
  

Combination Medications

Combination medications for allergies are designed to target multiple symptoms at once, making them a convenient option for individuals experiencing a variety of allergic reactions.

These medications often combine two or more active ingredients to address different aspects of allergies, such as nasal congestion, sneezing, and itching. For example, a combination of an antihistamine and a decongestant, such as loratadine and pseudoephedrine (found in Claritin-D).

While these combinations can be effective, they may not address the unique needs of every individual and can sometimes cause unwanted side effects. This is where Allermi provides a unique solution.

Unlike standard combination therapies, Allermi creates custom formulations based on your needs, which may include active ingredients like an antihistamine to block allergic reactions, a micro-dosed decongestant to relieve nasal stuffiness, and an anti-inflammatory agent to reduce swelling and irritation.

What sets Allermi apart is its personalized approach and convenience. Users receive a custom nasal spray kit designed to address their exact symptoms. If you’re looking for something that works immediately and is safe for long-term use, Allermi is an excellent choice. Learn more about the science behind Allermi here. 

Emergency Allergy Medicine

Emergency allergy medicines are designed to provide rapid relief during severe allergic reactions, such as anaphylaxis, where immediate treatment is critical to prevent life-threatening complications.

These medications work quickly to address symptoms such as swelling, difficulty breathing, or a drop in blood pressure. Common side effects vary by medication but are generally short-lived and manageable compared to the benefits of their life-saving effects.

Examples of emergency allergy medicine include:

• EpiPen
• Auvi-Q
• Adrenaclick
• Symjepi
• Generic epinephrine auto-injectors
  

The Bottom Line

Allergy medications are essential for managing symptoms. Antihistamines can relieve itching, while corticosteroid nasal sprays help with congestion. For severe allergies, epinephrine may be lifesaving. For nasal allergies, combination nasal sprays, which combine multiple medications like antihistamines and corticosteroids, address multiple symptoms like congestion and sneezing.

By using the right treatment, you can keep symptoms under control and live more comfortably. Always consult your healthcare provider to find the best plan for you.

References:

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2. R Simon, F. E., & Simons, K. J. (2008). H1 Antihistamines: Current Status and Future Directions. The World Allergy Organization Journal, 1(9), 145. https://doi.org/10.1186/1939-4551-1-9-145
3. Wahid, N. W. B., & Shermetaro, C. (2023c, September 4). Rhinitis medicamentosa. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK538318/
4. Barnes, P. J. (2010). Inhaled corticosteroids. Pharmaceuticals, 3(3), 514–540. https://doi.org/10.3390/ph3030514
5. ScienceDirect. (n.d.). Mast cell stabilizer. Retrieved January 22, 2025, from https://www.sciencedirect.com/topics/neuroscience/mast-cell-stabilizer
6. Choi, J., & Azmat, C. E. (2023, June 4). Leukotriene receptor antagonists. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK554445/