Volume 99, Issue s7

Leukotrienes play a major role in the underlying pathophysiology of asthma. Leukotriene-receptor antagonists and direct leukotriene-synthesis inhibitors may be important new agents in maintenance therapy for asthma. Their role may also extend to attenuating exercise-induced and allergen-induced bronchospasm. This article reviews the effectiveness of available leukotriene modifiers in various clinical studies, reviews their adverse effects profile, and discusses their potential roles in the management of asthma.

Azelastine hydrochloride is a nasally administered antihistamine that is effective and safe for the treatment of perennial and seasonal allergic rhinitis. In addition to acting as a histamine H1-receptor antagonist, azelastine also inhibits the production or release of many chemical mediators of the allergic response such as leukotrienes, free radicals, and cytokines. After nasal administration, azelastine is systemically absorbed with a bioavailability of about 40%. The side effects of azelastine are drowsiness, headache, and bitter taste. Azelastine has a rapid onset of action with a benefit in about 2 hours and a prolonged duration of activity (12 to 24 hours). Studies have shown azelastine to be more effective than placebo in terms of reduction of the major and total symptom complexes of allergic rhinitis. Comparison studies have demonstrated that azelastine is as effective as ebastine, loratadine, cetirizine hydrochloride, and terfenadine at symptom reduction, with varying results when compared with the corticosteroids budesonide and bedomethasone.Although there are conflicting studies, some have demonstrated that azelastine reduces the nasal congestion of allergic rhinitis. This feature that distinguishes it from oral antihistamines is of great interest because corticosteroids are known to be quite effective for the relief of nasal congestion, whereas the antihistamines are effective for the sneezing, itchy eyes, itchy nose, and watery eyes, but not the congestion. Azelastine nasal spray seems to be an efficacious treatment for allergic rhinitis with a rapid onset and long duration of activity, but without the systemic adverse effects of traditional sedating antihistamines.

Seasonal allergic conjunctivitis is rarely associated with permanent vision impairment; however, it is a relatively common condition that may compromise the quality of life. It may, in extreme cases, impair daily activities, including work. Numerous treatment options have become available for the relief of acute symptoms. Avoidance should always be the first line in therapy but, in most cases, is not practical, especially with pollen allergies. The use of saline eyedrops is simple and nontoxic, and it is effective in up to 30% to 35% of cases. It can and should be added to all other remedies to reduce adverse effects and cost by decreasing the need for other therapeutic options. Antihistamines and decongestants are useful treatment choices for the majority of cases. Ketorolac tromethamine may be helpful in relieving pruritus, but it offers little advantage over topical antihistamines. Corticosteroids may be used for severe cases for a limited time. If topical corticosteroids are being considered, an ophthalmologist should be consulted. Cromolyn sodium and lodoxarnide ophthalmic solution may be helpful in the prophylaxis of symptoms during the allergy season, but these agents require frequent dosing. Olopatadine hydrochloride is a mast cell stabilizer and antihistamine that can be dosed twice a day. Immunotherapy is effective and should be offered to those who are intolerant or have allergic conjunctivitis refractory to medications.