Everyday Allergy Relief: Is Daily Tablet Use Safe?

Approximately 1 in 3 Americans struggle with seasonal allergies, and many have concerns about taking daily allergy tablets. Are they safe to take long-term, and are there alternatives? How safe is it for children to take allergy medications? There are many options available to help the immune system ramp down it's overreaction to allergy triggers. These antihistamines have side effects, though, and new research suggests that the gut-lung axis may provide insights regarding the prevention and treatment of allergies.

Is it safe to use allergy tablets every day?

Yes, it is safe to take allergy tablets daily as indicated in the directions for use. Allergies are the immune system's overreaction to environmental triggers like pollen or grass. When the immune system responds more than it needs to, you notice the effects: itchy eyes, runny nose, sneezing, and irritated airways. These reactions are caused by histamines produced in response to your allergy triggers.

To calm down your allergy symptoms, your doctor may prescribe an antihistamine or recommend purchasing an over-the-counter brand. These medications include pills, chewable tablets, capsules, nasal sprays, liquids, and eye drops. Some examples of over-the-counter antihistamine tablets include:

• Brompheniramine (Dimetane)
• Cetirizine (Zyrtec)
• Chlorpheniramine (Chlor-Trimeton)
• Clemastine (Tavist)
• Diphenhydramine (Benadryl)
• Fexofenadine (Allegra)
• Loratadine (Alavert, Claritin)

When fluid fills the lining of your nasal passages, this can cause stuffiness and nasal congestion. Your doctor may recommend a decongestant, which may also come in pills or liquid form.

What about sprays?

Antihistamine nasal sprays such as azelastine (Astepro and Astelin) and olopatadine (Patanase) are available by prescription. They can be used safely once a day because they are non-habit-forming. These sprays should not be confused with corticosteroid nasal sprays, which are discussed below as an alternative allergy medication.

When using an antihistamine spray, read the directions carefully first. You may be directed to give a quick priming spray into the air first, then point the bottle tip straight back toward your sinuses and gently sniff as you squeeze. Spraying into the middle of your nose — the nasal septum — can be too forceful and potentially damage the septum. You do not need to tilt your head back, and you only need to sniff lightly. You do not want to taste the drug on the back of your throat because this will mean it did not stay in the sinuses where it needs to do its work.

Is it bad to take two different allergy pills in one day?

Generally speaking, you should ask your doctor before taking more than the recommended dose of any medication, even over-the-counter allergy tablets. Taking a precautionary approach is especially important for children or those with a cardiac condition. Some antihistamines can cause a change in cardiac rhythm, called long QT syndrome, when doubling up on the dose or mixing antihistamine brands.

What should I do if I think I need allergy tablets long-term?

If your allergies persist or worsen, the first step should be seeking an allergy evaluation and treatment. It is possible that the allergy tablets are providing only partial or temporary relief. Identifying the specific trigger will help you and your doctor evaluate which course of treatment will likely be most effective.

It is important to consult with your healthcare provider or pharmacist about any possible interaction of the allergy tablet with your current medications. In some cases, antihistamines can interfere with other medications like antibiotics and cause serious health problems.

Using over-the-counter nasal steroid sprays is a good addition to antihistamine allergy tablets. The nasal spray and antihistamine may work better than either alone. Finally, pollen counts are typically highest in the morning. Timing outdoor activities around the highest pollen counts may help reduce the severity of your symptoms.

Safest allergy medications for long-term use

It is safe to take allergy tablets daily, but there are reasons to consider only taking them if absolutely needed. The safest allergy medication to take for long-term use is the lowest dose of a single product that gives you the fewest side effects.

Each person has a unique response to medication. Pay attention to your fatigue, headaches, and dryness of the mouth, skin and eyes when taking an antihistamine, and make a note of the brand. When you switch brands, make similar notes for a few days so you can track which seems most effective. You may also try taking a few days off between medications so you have a real sense of your typical symptoms without medication.

Some allergy tablets will have both an antihistamine and a decongestant medication. Decongestant use should be minimized since it can elevate blood pressure, cause eye problems such as glaucoma, or worsen symptoms of thyroid disease. They can also make the person feel jittery or have difficulty sleeping.

Is it safe for children to take allergy tablets daily?

Many allergy medications are available for children as young as 6 years of age, and some as young as 2 years of age. Parents need to consider how quickly the medication takes effect (typically between 2 and 3 hours) and what side effects to expect. Children younger than 2 years should not be given allergy medications due to the risk of potentially serious side effects, such as convulsions, rapid heart rate, or death.

What are the side effects?

You may have heard that your body can build up tolerance to the drug, and it will not work as well over time — this is only true of older antihistamines and nasal decongestant sprays.

However, taking the antihistamine medications over a long period of time may cause side effects, such as:

• Dry eyes, blurry vision, trouble focusing, and worsening of itchy eyes
• Dry mouth, which can cause gum and tooth discomfort
• Poor appetite or stomach upset
• Nervousness or insomnia

Can the allergy tablet I take every day stop working and why?

While this phenomenon called tachyphylaxis or tolerance may be more pronounced with the older, sedating antihistamines, it can still occur with the newer medications on the market.

Antihistamines bind to histamine receptors on the surface of cells, blocking histamine from binding to the cell. However, the receptors can also signal without antihistamine binding. This means that even though a person is continuing to take an antihistamine, allergy symptoms can persist over time.

Some doctors recommend alternating between different antihistamines to prevent this type of tolerance to particular medications. However, most recent studies suggest that tolerance is much less likely to occur with the newer antihistamines, even with daily use.

Still, many people feel the antihistamines stop working. This may be because the person is experiencing worsening allergy symptoms instead of the antihistamines not working. In such cases, it may be helpful to have an allergy evaluation and modify the allergy treatment protocol. It is also possible that the person is experiencing non-allergic rhinitis caused by pollution, smoke, perfume, or other irritants that cause allergy-like symptoms but do not trigger histamine release. An evaluation can help sort out the specific triggers and find the appropriate treatment.

Are there alternatives to allergy tablets?

Corticosteroids are anti-inflammatory medications that suppress the immune response. These medications may be prescribed as an alternative to antihistamines and decongestants. Antihistamines must be taken before symptoms start to block the early allergy response caused by histamines. On the other hand, corticosteroid nasal sprays can be taken once symptoms start to block the late allergy response.

Allergy immunotherapy is very useful for those who feel their daily allergy tablets are no longer enough to control their symptoms.

Utilizing desensitization principles, allergy immunotherapy administers small doses of allergens to enhance immune tolerance, alleviating allergic reactions. Customized formulas cater to individual allergy profiles, commonly delivered via traditional shots or newer liquid methods for children. Although requiring months for effectiveness, maintenance dosing is essential for sustained symptom relief.

Another method that has become increasingly popular is sublingual immunotherapy. This means that allergy immunotherapy is custom mixed and used under the tongue in liquid form. Some formulations are small dissolvable tablets, while others are mixed in mouthwash or toothpaste, making them very popular with children and teenagers.

Can the 'gut-lung' axis help train my immune system?

The increase in allergic conditions over the past few decades has also attracted interest in the role of the gut microbiome. The gut contains approximately 70–80% of your immune system and is important in sorting out environmental triggers. Similarly, the human lung microbiota changes dramatically in the first years of life, and differences have been found in the level and diversity of the lung microbiota between healthy individuals and those having asthma and allergies.

Recent research related to the 'gut-lung' axis — the relationship between the gut microbiome and lung health — is very promising. Promoting a diverse gut microbiome has far-reaching effects on immune tolerance affecting all organs of the body.

Improving gut health through diet and lifestyle changes can reduce inflammation and increase allergen tolerance. This includes consuming pre- and probiotics and maintaining a balanced lifestyle with proper nutrition, exercise, sleep, stress management, and breathwork. Good gut health supports nutrient absorption and mental wellbeing, while attention to nutrition during pregnancy and early parenthood can lower the risk of allergies in infants.

Overall, allergy management presents a significant challenge, with preventive measures such as allergy tablets offering relief but potentially posing long-term risks. Understanding the interplay between the microbiome and the immune system holds promise for allergy prevention and treatment, spanning various conditions. It is never too late to start making important changes in our lifestyle to improve overall health and reduce systemic inflammation.

Article history

Our experts strive to provide up to date information and update articles when new information becomes available

January 03, 2023

Fact checked by Alifia Fernandes Jokubauskienė, MPharm

January 03, 2023

Co-written by Allison Krug, MPH

January 03, 2023

Written by Drew Sutton, MD