Patadin-2

Uses

Patadin-2 Nasal Spray is an H1 receptor antagonist used for the relief of the symptoms of seasonal allergic rhinitis in adults and children 6 years of age and older.

Patadin-2 is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Seasonal Allergic Conjunctivitis, Seasonal Allergic Rhinitis

How Patadin-2 works

Histamine is a biogenic vasoactive amine that binds to its receptors, which are G-protein coupled receptors. Signaling through the histamine H1 receptor is thought to primarily promote the activation of inflammatory reactions, such as allergy, asthma, and autoimmune diseases. H1 receptor signaling activates the intracellular transcription factors, such as IP3, PLC, PKC, DAG, and intracellular calcium ions, which all work to activate further downstream cascades. Activated downstream cascades lead to the production of cytokines, the release of mast cell inflammatory mediators, synthesis of prostacyclins, activation of platelet factor, as well as the synthesis of nitric oxide, arachidonic acid, and thromboxane, which all contribute to inflammatory reactions.

Patadin-2 is an anti-allergic molecule that works via several mechanisms. As a mast cell stabilizer, it stabilizes rodent basophils and human conjunctival mast cells and inhibits the immunologically-stimulated release of histamine. Patadin-2 acts as an antagonist at the histamine H1 receptors with high selectivity, which is explained by a unique receptor binding pocket that consists of the aspartate residue in the third transmembrane helix and other sites in the H1 receptor. Upon binding, olopatadine blocks the H1 receptor signaling pathway, inhibiting the release of inflammatory mediators, such as tryptase, prostaglandin D2, TNF-alpha, as well as pro-inflammatory cytokines. It also decreases chemotaxis and inhibits eosinophil activation. In vitro, olopatadine was shown to inhibit epithelial cell intercellular adhesion molecule-1 (ICAM-1), which promotes the recruitment of migrating pro-inflammatory mediators.

Dosage

Patadin-2 dosage

Adults and Adolescents 12 years of age and older: Two sprays per nostril twice daily.

Children 6 to 11 years of age: One spray per nostril twice daily.

Administer Patadin-2Nasal Spray by the intranasal route only.

Side Effects

A bitter taste in the mouth, nosebleeds, or irritation/soreness in the nose may occur. Drowsiness may rarely occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Toxicity

Based on the findings of an acute toxicity study in animals, the oral LD₅₀ of olopatadine was >1150 mg/kg in mice and >3870 mg/kg in rats. The Lowest published toxic dose via the oral route was 20 mg/kg in rat and 0.1 mg/kg in mouse.

There are no known reports on overdosage following oral, ophthalmic, or intranasal administration of olopatadine. Likely symptoms of antihistamine overdose may include drowsiness in adults and, initially, agitation and restlessness, followed by drowsiness in children. In case of suspected overdose, supportive and symptomatic treatment is recommended.

Precaution

Before initial use, Patadin-2 Nasal Spray by releasing 5 sprays or until a fine mist appears. When Patadin-2 Nasal Spray has not been used for more than 7 days, re-prime by releasing 2 sprays. Avoid spraying Patadin-2 Nasal Spray into the eyes. Patients should be informed to avoid spraying Patadin-2 Nasal Spray in their eyes.

Interaction

Interaction with other medications have not been investigated.

Food Interaction

Volume of Distribution

In an open-label study consisting of healthy Chinese subjects receiving oral administration of olopatadine, the mean apparent volume of distribution was 133.83 L.

Elimination Route

Ocular administration of olopatadine in healthy subjects resulted in the Cmax of 1.6 ± 0.9 ng/mL, which was reached after about 2.0 hours. The AUC was 9.7 ± 4.4 ngxh/mL.

The average absolute bioavaiability of intranasal olopatadine is about 57%. Following intranasal administration in healthy subjects, the Cmax of 6.0 ± 8.99 ng/mL at steady-state was reached between 30 minutes to 1 hour after twice daily intranasal administration. The average AUC was 66.0 ± 26.8 ng·h/mL. In patients with seasonal allergic rhinitis, the Cmax of 23.3 ± 6.2 ng/mL at steady-state was reached between 15 minutes and 2 hours post-dosing and the average AUC was 78.0 ± 13.9 ng·h/mL.

Half Life

Following ocular administration, the elimination half-life of olopatadine was 3.4 ± 1.2 hours. In oral pharmacokinetics study, the elimination half-life was reported to be 8 to 12 hours.

Clearance

In an open-label study consisting of healthy Chinese subjects receiving oral administration of olopatadine, the mean apparent oral clearance (CL/F) was 23.45 L/h.

Elimination Route

Patadin-2 is mainly eliminated through urinary excretion. Following oral administration, about 70% and 17% of the total dose was recovered in the urine and feces, respectively.

Pregnancy & Breastfeeding use

Pregnancy Category C; No adequate and well-controlled studies in pregnant women have been conducted. Patadin-2 Nasal Spray should be used in pregnant women only if the potential benefit to the mother justifies the potential risk to the embryo or fetus.

Lactation: It is not known whether topical nasal administration could result in sufficient systemic absorption to produce detectable quantities in human breast milk. Patadin-2 Nasal Spray should be used by nursing mothers only if the potential benefit to the patient outweighs the potential risks to the infant.

Special Warning

There have been no reported overdoses with Patadin-2 Nasal Spray.

Innovators Monograph

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