Is Your Allergy Medicine Not Working? — A Guide About Desensitization and Clinical Tolerance

What Is Allergy Medicine?

Before we explore why your allergy medicine might fall short, it's essential to understand what exactly these medications are and how they function.

Allergy medicine encompasses a broad spectrum of drugs designed to counteract your body's immune response to allergens, substances that trigger allergic reactions.

Common forms of allergy medicine include antihistamines, decongestants, nasal corticosteroids, and anti-leukotrienes (leukotriene modifiers), each targeting specific aspects of your allergic response.

While these medications often provide short-term relief, their efficacy can be compromised over time, prompting the need to explore the biological mechanisms at play. [1]

So, how does allergy medicine work explicitly?

How Does Allergy Medicine Work Biologically? — The Battle Within

Allergic reactions result from the immune system's hypersensitivity to otherwise harmless substances. When a person with an allergy encounters an allergen, their immune system goes into overdrive, releasing histamines and other chemicals. [2] The immune system perceives this allergen, which is objectively a harmless substance, as a threat and leads to a cascade of biological processes to protect you from said substance – which is then referred to as “allergen.”

The main player in this allergic reaction from the immune system is histamine. The body releases histamines as part of the immune response when it encounters allergens, triggering an inflammatory reaction designed to defend against perceived threats. Histamine binds to H2 re­ceptors to induce smooth muscle di­lation and endothelial gaping, which leads to redness and swelling. Histamine also binds to the H1 receptors, leading to the itching characteristic of allergy. Without getting into further detail, histamines promote increased blood flow, vascular permeability, and mucus production, contributing to typical allergy symptoms like itching, sneezing, and congestion. [2]

Therefore, the majority of allergy medicine is based on prohibiting the release of histamines by using antihistamines. Antihistamines work by blocking the action of

Said histamines, thereby alleviating and preventing allergy symptoms. [2]

Other medications, such as nasal corticosteroids, target inflammation more directly in the nasal passages, reducing congestion and improving airflow.

However, the effectiveness of these medications can be compromised over time, leaving people to grapple with persistent symptoms.

Why Do Antihistamines Stop Working? — Developing Tolerance to Allergy Medicine

Despite their initial effectiveness, antihistamines can lose their efficacy over time, a phenomenon known as tachyphylaxis. Is this the scourge of our modern lives? Well, no. Tachyphylaxis is not a new development but has already been described for 45 years. [3]

But what is tachyphylaxis?

Tachyphylaxis – A Potential Reason Why Your Allergy Medicine Is Not Working

Tachyphylaxis refers to a cell's or tissue's loss of sensitivity to a therapeutic drug, like an allergy drug, or a desensitization of re­sponse, but not necessarily a desensitization of re­ceptors. When the body becomes tolerant to the effects of your allergy drug, necessitating higher doses for the same relief or rendering the medication ineffective altogether might be necessary. [3]

One reason behind this tolerance or desensitization can be the downregulation of histamine receptors. Another reason why histamine tachyphylaxis occurs is because of a compensatory in­crease in the number of H2 receptors in response to histamine antagonists. [4] When exposed to antihistamines for an extended period, your body may produce more histamine receptors, diminishing the drug's impact.

Additionally, environmental changes, your allergy treatment plan, and the nature of the allergen itself can contribute to the development of tolerance.

The Top 6 Reasons Why Your Allergy Medicine Is Not Working

CARE has summarized the most frequent reasons why your allergy medicine doesn't work in the below list:

• Tolerance Development: Over time, your body may become tolerant to the active ingredients in your allergy medication, requiring higher doses for the same relief or rendering the medication less effective.

Are your antihistamines not working? Prolonged use of antihistamines can lead to the downregulation of histamine receptors, reducing the impact of the medication on blocking histamine release and alleviating symptoms. [3] [4]

• Environmental Changes: Changes in your living environment or exposure to new allergens may contribute to a decrease in the effectiveness of your current allergy medicine. It's essential to reassess and adapt your treatment plan based on changes in your surroundings. [5]

• Nature of the Allergen: The specific allergen triggering your symptoms may play a role in the effectiveness of your allergy medicine. If you're exposed to a new or more potent allergen, your current medication might not be sufficient to manage the heightened immune response. Furthermore, seasonal allergies get worse and prolonged with climate change. Adjustments to your treatment plan may be necessary to address seasonal and environmental changes in allergen exposure. [6]

• Incomplete Symptom Coverage: Your allergy medication may not be addressing all aspects of your symptoms. For example, if you're using only antihistamines and your symptoms involve a stuffy and runny nose, nasal corticosteroids may be necessary for comprehensive relief.

• Incorrect Diagnosis or New Allergy: Your allergy symptoms might have evolved, or you may have developed new allergies that require a different treatment approach. Reassessing your allergy diagnosis through new allergy testing with a healthcare professional can help tailor your treatment more effectively.

• Non-Adherence to Medication Schedule: Consistency is key when taking allergy medication. Missing doses or not adhering to the prescribed schedule can impact the medication's effectiveness.

Can You Develop A Tolerance Toward Allergy Meds?

The development of tolerance towards allergy medications is a genuine concern for many people, leading to frustration and a sense of helplessness. Will you ever get rid of your stuffy nose and itchy eyes? Rest assured, not everyone will experience histamine tachyphylaxis, and the degree of tolerance or desensitization can vary widely among individual people.

Moreover, healthcare professionals can employ strategies to mitigate your risk of tolerance, such as periodic breaks from medication, rotating between different classes of drugs, and exploring alternative treatments like immunotherapy for allergy relief.

By taking a proactive and individualized approach, it's possible to manage your allergies without solely relying on histamines.

What Should I Do When My Allergy Medications Don’t Work Anymore?

When faced with diminishing returns from allergy medicine, people often wonder about alternative strategies for managing their symptoms. It's crucial to consult a healthcare professional to explore personalized solutions. Some recommendations may include reassessing your allergy diagnosis, identifying and avoiding specific year-round allergy triggers like dust mites and dander, and adjusting your individual treatment plan. If you do not get relief from your allergy symptoms, this can result in a sinus infection.

In cases where over-the-counter medications (OTC), like Allegra and Zyrtec, prove insufficient, a transition to prescription-strength alternatives may be necessary. Prescription medications often offer a more potent and targeted approach, addressing your unique challenges when you face a stubborn or severe allergy.

1. Consult a Healthcare Professional: Schedule an appointment with your doctor or allergist to reassess your symptoms and medication effectiveness.
2. Review and Update Diagnosis: Ensure your allergy diagnosis is accurate and up-to-date, considering potential changes in your allergen exposure or new sensitivities.
3. Explore Prescription Options: Discuss the possibility of transitioning to prescription-strength medications for a more targeted and potent approach if you experience histamine tachyphylaxis.
4. Consider Immunotherapy: Explore immunotherapy options, such as allergy shots or sublingual tablets, to address the root cause of allergies and potentially achieve long-term relief. [7]
5. Identify and Avoid Allergy Triggers: Work with your healthcare provider to identify specific triggers and develop strategies to minimize exposure in your environment.
6. Adherence to Medication Schedule: Ensure consistent adherence to your prescribed allergy medication schedule, as irregular use can impact effectiveness.
7. Lifestyle Adjustments: Address lifestyle factors like stress, sleep, and diet, as they can worsen allergy symptoms and, consequently, treatment efficacy. [8]
8. Evaluate Overall Health: Rule out underlying health conditions that may complicate allergy management. Your regular health check-ups with your CARE membership assess your overall health status and can help you detect changes in your body early on.

Immunotherapy – A Long-Term Solution For Allergy Relief

For those seeking a more long-term solution, immunotherapy stands out as a transformative approach to allergy management.

Immunotherapy involves exposing people to gradually increasing doses of allergens, allowing the immune system to build tolerance over time. This can be achieved through allergy shots or sublingual immunotherapy (under-the-tongue tablets). [7]

Immunotherapy not only addresses the symptoms but aims to modify the underlying immune response, offering a potential cure for certain allergies.

While immunotherapy requires commitment and patience, the benefits can be profound, providing lasting relief beyond what traditional allergy medications can achieve. Please be aware that immunotherapy is an option for specific allergens only.

Is Your OTC Allergy Meds Not Working? — Prescription Medication Instead of OTC

For those allergy sufferers where immunotherapy is unfortunately not an option, changing their allergy medicine from over-the-counter medications to prescription drugs might be a solution. While OTC are convenient and readily accessible, they may fall short for individuals with more complex or severe allergy symptoms, or you can develop a desensitization or tolerance to nasal steroids or antihistamine drugs. [3] [9]

Healthcare professionals may recommend prescription-strength alternatives, which often contain higher doses of active ingredients or different classes of drugs.

Prescription allergy medications allow for a more tailored and potent approach, addressing the unique challenges faced by people with allergy medicine tolerance or persistent and severe allergies. These medications may include prescription antihistamines, multi-mechanism anti-allergy drugs, nasal corticosteroids, or other specialized drugs, providing a more robust defense against allergic reactions. [10] [11]