Azelastine is a synthetic antihistamine medication used to relieve allergic symptoms. Its pharmacological action involves selective antagonism of histamine h1 receptors located on peripheral tissues. By blocking these receptors it prevents the binding of histamine and reduces the cascade of inflammatory events triggered by allergic reactions. The drug is absorbed after oral administration and distributes to tissues including the nasal mucosa where it exerts local activity. Its onset of action occurs within minutes due to rapid availability at the site of application when administered as a nasal spray. It also exhibits anti-inflammatory properties that are unrelated to histamine receptor blockade and contribute to its therapeutic effect. The elimination of Azelastine proceeds primarily through hepatic metabolism with minimal renal excretion. Overall the medication provides symptom relief by stabilizing mast cells indirectly and by inhibiting the release of additional inflammatory mediators.

Azelastine is a second generation antihistamine used to relieve allergy symptoms such as sneezing and itching. It works by blocking the h1 histamine receptor on cells involved in allergic responses. By inhibiting histamine binding the drug prevents the release of inflammatory chemicals that cause swelling and mucus production. This action stabilizes mast cells and reduces the body's overreaction to allergens. Azelastine is formulated as a nasal spray that delivers the medication directly to the lining of the nose where it can quickly counteract local allergic inflammation. The combined antihistamine and anti inflammatory effects provide symptomatic relief without the need for systemic drugs.

Side effects of Azelastine can include mild nasal irritation dry mouth and headache. Some users may experience a temporary bitter taste after spraying the medication. Nasal bleeding or crusting can occur in rare cases but is usually not serious. Eye irritation may develop if the spray contacts the surrounding tissues. Drowsiness or fatigue has been reported in a small number of patients. Less commonly localized skin reactions such as itching or rash may appear at the application site. The frequency of serious adverse events is low and most symptoms resolve without intervention. Most reported side effects are mild and tend to resolve on their own.

Azelastine may cause mild irritation of the nasal passages after spray application. Some users report a bitter taste sensation following ocular or nasal use. Headache is also listed as a frequent complaint in clinical observations. Dryness of the throat can occur when the medication is inhaled. Occasionally, users experience drowsiness or fatigue. Visual disturbances such as blurred vision are rare but documented side effects. Injectable formulations of Azelastine are associated with temporary redness at the injection site.