Azelastine hydrochloride

Uses

Azelastine hydrochloride nasal spray is used for the treatment of the symptoms of seasonal allergic rhinitis such as rhinorrhea, sneezing, and nasal pruritus in adults and children 5 years and older, and for the treatment of the symptoms of vasomotor rhinitis, such as rhinorrhea, nasal congestion and postnasal drip in adults and children 12 years and older.

Azelastine hydrochloride is also used to associated treatment for these conditions: Allergic Eye Disease, Allergic Rhinitis (AR), Atopy Keratoconjunctivitis, Blepharitis allergic, Conjunctivitis allergic, Pollen Allergy, Seasonal Allergic Conjunctivitis, Seasonal Allergic Rhinitis, Vasomotor Rhinitis

How Azelastine hydrochloride works

Azelastine hydrochloride is primarily a selective antagonist of histamine H1-receptors, with a lesser affinity for H2-receptors, used for the symptomatic treatment of allergies. Histamine H1-receptors are G-protein-coupled receptors with 7 transmembrane spanning domains that are found on nerve endings, smooth muscle cells, and glandular cells. Following allergen exposure in sensitized individuals, IgE-receptor cross-linking on mast cells results in the release of histamine, which binds to H1-receptors and contributes to typical allergic symptoms such as itching, sneezing, and congestion.

Though its primary mode of action is thought to be via H1-receptor antagonism, azelastine (like other second-generation antihistamines) appears to affect other mediators of allergic symptomatology. Azelastine hydrochloride has mast cell-stabilizing properties that prevent the release of interleukin-6, tryptase, histamine, and TNF-alpha from mast cells, and has been shown to reduce mediators of mast cell degranulation such as leukotrienes in the nasal lavage of patients with rhinitis, as well as inhibiting their production and release from eosinophils (potentially via inhibition of phospholipase A₂ and leukotriene C₄ synthase). Additionally, patients using oral azelastine were observed to have significantly reduced concentrations of substance P and bradykinin in nasal secretions, both of which may play a role in nasal itching and sneezing in patients with allergic rhinitis.

Dosage

Azelastine hydrochloride dosage

Adult and children 12 years and older: 2 sprays in each nostril twice daily.

Children 5-11 years of age: 1 spray in each nostril twice daily.

Initial pump priming requires seven sprays of the pump. If used regularly as recommended, no further priming is required. If not used more than 24 hours, the pump will require 2 sprays, or if not used for more than seven days, the pump will require 7 sprays.

Side Effects

Headache, dizziness, sneezing, nosebleed, nausea, stinging or itching in nose, dry mouth, sore throat, bitter taste etc.

Toxicity

Overdosage of intranasal or ophthalmic azelastine is unlikely to result in clinically significant adverse effects aside from increased drowsiness. If overdose does occur, employ general supportive measures. Oral ingestion of antihistamines, including non-oral formulations of azelastine, can cause serious adverse effects in children - for this reason, these products should be kept out of the reach of children. The oral LD₅₀ in rats is 580 mg/kg.

Precaution

In clinical trials, the occurrence of somnolence has been reported in some patients taking Azelastine hydrochloride nasal spray; due caution should therefore be exercised when driving a car or operating potentially dangerous machinery. Concurrent use of this nasal spray with alcohol or other CNS depressants should be avoided because additional reductions in alertness and additional impairment of CNS performance may occur.

Interaction

It is especially important to check before combining Azelastine hydrochloride nasal spray with Alcohol, CNS depressants, Cimetidine & Ketoconazole.

Food Interaction

• Avoid alcohol. Ingesting alcohol may cause additive CNS depressant effects.

Volume of Distribution

After intravenous and oral administration, the steady-state volume of distribution is 14.5 L/kg.

Elimination Route

Systemic bioavailability of azelastine hydrochloride following intranasal administration is approximately 40%, reaching Cmax within 2-3 hours. When administered at doses greater than the recommended maximum, greater than proportional increases in both Cmax and AUC were observed.

Half Life

Based on intravenous and oral administration, azelastine demonstrated an elimination half-life of 22 hours. Its primary active metabolite, desmethylazelastine, has an elimination half-life of 54 hours.

Clearance

Based on intravenous and oral administration, azelastine demonstrated a plasma clearance of 0.5 L/h/kg.

Elimination Route

After an oral dose of radio-labeled azelastine hydrochloride, approximately 75% was excreted in the feces, with less than 10% as unchanged azelastine hydrochloride.

Pregnancy & Breastfeeding use

Use in pregnancy: The effects of Azelastine hydrochloride during pregnancy have not been adequately studied. Azelastine hydrochloride should be administered during pregnancy, if the potential benefit justifies the potential risks to fetus.

Use in nursing mother: It is not known whether Azelastine hydrochloride is excreted in human milk. However, caution should be exercised when Azelastine hydrochloride is administered to a nursing mother.

Contraindication

Contraindicated in patients with a known hypersensitivity to Azelastine hydrochloride or any of its components.

Special Warning

Use in children: The safety and effectiveness of Azelastine hydrochloride nasal spray in patients below 5 years of age have not been established.

Storage Condition

Keep out of reach of children. Store in a cool and dry place protected from light. Do not freeze.

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