Drugs for Allergic Rhinitis

Overview of Allergic Rhinitis

Allergic rhinitis is characterized as an inflammation of the nasal mucosa, commonly presenting symptoms such as sneezing, itchy nose, itchy eyes, watery rhinorrhea, nasal congestion, and occasionally a non-productive cough. The condition is typically provoked by inhaling various allergens such as dust, pollen, or animal dander. Upon inhalation, these allergens interact with mast cells that are coated with Immunoglobulin E (IgE) antibodies, produced from prior allergen exposure. This interaction triggers mast cells to release inflammatory mediators like histamine, leukotrienes, and chemotactic factors, leading to bronchiolar spasms and mucosal thickening due to edema and inflammatory cell infiltration.

Treatment Strategies

The primary goal in treating allergic rhinitis is to minimize these inflammatory processes, utilizing several classes of medications:

Antihistamines

Antihistamines play a crucial role by blocking the effects of histamine, alleviating symptoms such as sneezing and itching. They are most effective when used preventively, particularly for mild or intermittent symptoms rather than as a rescue treatment.

• First-generation Antihistamines: Examples include diphenhydramine (Benadryl), which are less favored now due to their sedative and anticholinergic effects.

• Second-generation Antihistamines: These include cetirizine (Zyrtec), loratadine (Claritin), desloratadine, fexofenadine (Allegra), and levocetirizine (Xyzal). These newer antihistamines are generally better tolerated and have fewer effects on the central nervous system.

• Intranasal and Ophthalmic Antihistamines: Such as olopatadine and azelastine, provide localized relief while minimizing systemic side effects.

Intranasal Corticosteroids

For a more comprehensive treatment of allergic rhinitis, intranasal corticosteroids are often the preferred option as they tackle underlying inflammation and effectively reduce nasal congestion and rhinorrhea. Common intranasal corticosteroids include:

• Beclomethasone

• Budesonide

• FluticasoneThese medications have a delayed onset of action (ranging from 3 to 36 hours), and it may take 1 to 2 weeks for patients to experience maximum therapeutic effects. Patients must be educated about this delay in onset. Side effects are typically localized to the nasal passages, with potential irritations, nosebleeds, sore throat, or rare cases of fungal overgrowth (candidiasis).

Alpha Adrenergic Agonists

These short-acting nasal decongestants, including phenylephrine and oxymetazoline, are effective for reducing nasal airway resistance by constricting dilated arterioles in the nasal mucosa. While they provide rapid relief for acute allergic rhinitis symptoms, they should not be used for more than three consecutive days due to rebound nasal congestion risks. Oral formulations like phenylephrine and pseudoephedrine offer longer durations but can result in systemic side effects, especially concerning blood pressure and heart rate—hence, should be used cautiously in patients with cardiovascular risks.

Additional Therapies

• Intranasal Cromolyn: It is a prophylactic therapy that must be initiated 1 to 2 weeks before expected allergen exposure.

• Leukotriene Receptor Antagonists: Such as montelukast (Singulair) can serve as monotherapy or in combination, especially beneficial for patients with concurrent asthma and allergic rhinitis.

• Intranasal Ipratropium: Primarily effective in addressing rhinorrhea, though it does not alleviate sneezing or nasal congestion.

Case Management Strategies

For successful management of allergic rhinitis, particularly for patients with predictable allergies, it is important to educate them on anticipatory dosing, such as starting treatment before known allergen exposure (like ragweed season). This proactive approach can significantly minimize symptomatic flare-ups and enhance quality of life.