Medications for Allergy

A woman in her early thirties wants some advice. She tells you that she has hay fever and a blocked nose and is finding it difficult to breathe. You find out that she has had the symptoms for a few days; they have gradually got worse. She gets hay fever every summer and it is usually controlled by chlorphenamine tablets, which she buys every year and which she is taking at the moment. As a child, she suffered quite badly from eczema and is still troubled by it occasionally. She tells you that she has been a little wheezy for the past day or so, but she does not have a cough, and has not coughed up any sputum. She is not taking any other medicines.

The pharmacist’s view

This woman has a previous history of hay fever, which has, until now, been dealt adequately with chlorphenamine tablets. Her symptoms have worsened over a period of a few days and she is now wheezing. It seems unlikely that she has a chest infection, which could have been a possible cause of the symptoms. She should be referred to the doctor at once since her symptoms suggest more serious implications such as asthma.

The doctor’s view

This woman should be referred to her doctor directly. She almost certainly has seasonal asthma. In addition to the hay fever treatment recommended by her pharmacist, it is likely that she would benefit from a steroid inhaler such as beclometasone. Depending on the severity of her symptoms, she would probably be prescribed a beta-agonist, such as a salbutamol inhaler, as well. This consultation is a complex one for a doctor to manage in the usual 10 min available in view of the time required for information-giving, explanation about the nature of the problem, the rationale for the treatments and the technique of using inhalers.

The use of intranasal corticosteroids is increasingly becoming first-line therapy for many patients with allergic rhinitis, especially those with moderate to severe symptoms or those with perennial allergic rhinitis in which nasal symptoms predominate. Intranasal corticosteroids specifically inhibit the allergic inflammatory processes that contribute to the late-phase response of nasal congestion. When used prophylactically, they can also inhibit the early-phase response to allergens. Overall, they are effective in relieving sneezing, nasal itching, rhinorrhea, and congestion.

Table 3 lists available intranasal corticosteroids, along with dosing information and comparative costs. In general, these agents are considered more cost-effective for use as monotherapy than 2nd-generation antihistamines. A recent meta-analysis found intranasal corticosteroids to be more effective than oral antihistamines in reducing nasal blockage, nasal discharge, sneezing, nasal itch, postnasal drip, and total nasal symptoms. No significant difference was detected for nasal discomfort, nasal resistance, and eye symptoms. No particular product has demonstrated clinical superiority, selection of drug should be based on factors such as response, ease of administration, cost, and formulation.

Table 3 Intranasal corticosteroids

Application site irritation (e.g., nasal irritation, burning, or sneezing after administration) is the most commonly encountered side effect. Patients complaining of local irritation may be switched to various aqueous formulations. Although rare, mucosal erosion and septal perforations have been reported with long-term use. To minimize septal irritation, patients should be instructed to direct the spray upwards and toward the lateral portion of the nose. Periodic examination of the nasal septum should be performed.

Although systemic effects from intranasal corticosteroids at recommended doses are considered minimal, there are some concerns regarding long-term exposure. Reports of posterior subcapsular cataract formation have been linked with the use of intranasal or inhaled corticosteroids; however, more recent prospective trials did not reveal evidence of posterior subcapsular cataract formation or elevation in intraocular pressure.

In 1998, the FDA’s advisory committees on pulmonary and allergy drugs and on metabolic endocrine drugs convened to assess data suggesting that intranasal corticosteroids may have an effect on growth velocity in children. Consequently, a new class labeling for pediatric use of inhaled and intranasal corticosteroids was mandated. At this time, the long-term significance of growth velocity reduction on final adult height is unknown. The FDA recommends routine monitoring of growth in pediatric patients using intranasal corticosteroids and titration to the lowest effective dose to minimize systemic risks.

Patient education is essential in ensuring proper use and compliance to intranasal corticosteroid therapy. Patients should be instructed on instillation techniques and informed about the possible delay in symptomatic response. Assessment of maximal response may require a therapeutic trial of several weeks. The drug should be administered regularly on a daily basis, rather than as needed for rescue relief.

For patients with severe disease, the combined use of intranasal corticosteroids and antihistamines may be necessary to control symptoms. The use of oral corticosteroids should be reserved for patients with severe exacerbations or intractable disease due to high risk of systemic adverse effects.