INITIAL CHOICE OF AGENT
The selection of initial therapy involves several factors. In general, patients with moderate to severe allergic rhinitis symptoms should start with an intranasal corticosteroid, whereas those with milder intermittent symptoms can be treated with a second-generation oral or intranasal antihistamine.1 In patients with nonallergic rhinitis, either an intranasal corticosteroid or an intranasal antihistamine is appropriate; however, an oral antihistamine is not likely to be effective. Patients with prominent nasal congestion can be treated with an intranasal corticosteroid or perhaps an intranasal antihistamine. Patients whose most prominent symptom is clear anterior rhinorrhea, such as those with gustatory rhinitis, benefit most from intranasal ipratropium.
Frequently, a single agent does not sufficiently relieve the symptoms of allergic rhinitis. Because oral antihistamines treat all allergic rhinitis symptoms effectively except congestion, and oral decongestants treat only congestion, the combination makes pharmacological sense. Indeed, the evidence shows that this combination is superior to either agent alone for symptoms of allergic rhinitis.29 However, the adverse effects of oral decongestants make this combination untenable for sustained use in many patients.
An oral antihistamine plus montelukast(Drug information on montelukast) may be superior to either agent alone for allergic rhinitis,30-32 but this combination is inferior to an intranasal corticosteroid by itself.32,33 Nevertheless, select patients may demonstrate marked clinical improvement, even the minority in whom intranasal corticosteroids have failed. For rhinorrhea, intranasal ipratropium and an intranasal corticosteroid are more effective than either agent alone.25
Other frequently used combinations, such as an oral antihistamine plus an intranasal corticosteroid33,34 and an oral antihistamine plus an intranasal antihistamine,17,35 are not supported by clearly convincing data that indicate additive benefit. However, from a practical standpoint, the combination of an intranasal corticosteroid used daily and an oral second-generation antihistamine used as needed is often quite effective. In patients who do not respond to this regimen, an intranasal antihistamine and an intranasal corticosteroid may be the most potent 2-agent combination.36
|•||Intranasal corticosteroids are the most effective medications for allergic rhinitis; they treat all of its symptoms. These agents are also effective in nonallergic rhinitis, including vasomotor rhinitis and rhinitis medicamentosa.|
|•||Most patients who report that allergic rhinitis symptoms have not responded to an intranasal corticosteroid are not using the medication regularly. Advise patients to give the medication at least a 1-month trial. In addition, teach them to direct the spray laterally within the nasal vestibule; this technique minimizes the nasal irritation and bleeding that can be associated with intranasal corticosteroids.|
|•||Second-generation oral antihistamines are effective for pruritus and rhinorrhea in allergic rhinitis, although they are less effective for nasal congestion and are of no proven use in nonallergic rhinitis.|
|•||To prevent the development of rebound congestion (rhinitis medicamentosa), advise patients not to use intranasal decongestants for more than 3 days.|
|•||In general, patients with moderate to severe allergic rhinitis symptoms should start with an intranasal corticosteroid, whereas those with milder intermittent symptoms can be treated with a second-generation oral or intranasal antihistamine.|
|•||Consider referral to an allergist for patients whose rhinitis remains symptomatic or whose quality of life remains impaired despite treatment.|
|•||Subcutaneous injection allergen immunotherapy has been shown to be effective in numerous randomized, controlled trials in children and adults. Immunotherapy also appears to prevent sensitization to new allergens and may reduce the risk of asthma in patients with allergic rhinitis.|