Olopatadine

Olopatadine is a medication primarily used to treat allergic conjunctivitis, also known as eye allergies. It belongs to a class of drugs called antihistamines, which work by blocking the effects of histamine, a chemical that is released during an allergic reaction.

Olapatadine is used in the treatment of Seasonal Allergic Rhinitis.

Olopatadine eye drops are absorbed through the conjunctiva and cornea of the eye and enter the systemic circulation. Olopatadine nasal spray is absorbed through the nasal mucosa. Olopatadine is distributed throughout the body and crosses the blood-brain barrier. It has a moderate volume of distribution. Olopatadine is metabolized in the liver by the cytochrome P450 enzyme system, primarily by CYP3A4 and CYP2D6. The major metabolite of olopatadine is desmethyl olopatadine, which is inactive.

Olopatadine and its metabolites are excreted primarily in the urine. The elimination half-life of olopatadine is approximately 3 hours, while the elimination half-life of desmethyl olopatadine is approximately 26 hours.

the Tmax is approximately 2-3 hours after administration.

Cmax of Olopatadine after a single oral dose 5-7 ng/mL.

Olopatadine shows common side effects like Headache, Dry mouth, Fatigue or drowsiness, Nausea, Stomach upset, Nervousness, Difficulty sleeping and Skin rash or itching.

Olopatadine is available in Solution, Spray, Drops.

Olopatadine is available in India, Germany, Canada, France.

Olopatadine is a H1 receptor antagonist, olopatadine binds to and blocks the histamine H1 receptors located on cells in the body that are responsible for mediating the allergic response, such as the cells in the eyes and nose. By blocking these receptors, olopatadine can reduce the symptoms of allergic reactions, including itching, redness, and swelling.

Olopatadine is available in the form of Solution, Spray, Drops.

Olapatadine is used in the treatment of Seasonal Allergic Rhinitis.

Olopatadine is a relatively selective histamine H₁-receptor antagonist which inhibits the release of histamine from mast cells and histamine-induced effects on conjunctival epithelial cells. It shares many of the pharmacologic effects of mast cell stabilizers.

Olopatadine is approved for use in the following clinical indications

Seasonal allergic rhinitis: Treatment of the symptoms of seasonal allergic rhinitis in adults and pediatric patients ≥6 years of age.

Nasal

Seasonal allergic rhinitis

Adult: As 0.6% spray: 2 sprays into each nostril bid.

Child: 6-11 year 1 spray into each nostril bid.

Ophthalmic

Allergic conjunctivitis

Adult: As 0.1% soln: 1 drop in the affected eye(s) bid at an interval of 6-8 hr. As 0.2% soln: 1 drop in the affected eye(s) once daily.

Child: ≥3 yr Same as adult dose.

Olopatadine is available in the dosage strength of

• 10 mg.

Take after eating and with a full glass of water to decrease gastric upset.

Hypersensitivity: Olopatadine should not be used in individuals who have a known hypersensitivity or allergy to the medication or any of its components.

Pediatric use: Olopatadine is not recommended for use in children under the age of 3 years for the treatment of allergic rhinitis and under the age of 2 years for the treatment of allergic conjunctivitis.

Pregnancy and breastfeeding: The safety of olopatadine use during pregnancy and breastfeeding has not been established, and its use should be avoided or used with caution in these situations.

Severe renal impairment: Olopatadine should be used with caution in individuals with severe renal impairment, as it may accumulate in the body and increase the risk of side effects.

It is important to talk to a healthcare professional before using olopatadine to determine if it is safe and appropriate for individual use.

Concerns related to adverse effects:

• CNS depression: May cause drowsiness in some patients; instruct patient to use caution when driving or operating machinery. Effects may be additive with CNS depressants and/or ethanol.

• Nasal ulcerations: Periodically examine nasal mucosa for ulceration and consider discontinuing if ulceration occurs.

Olopatadine may cause liver problems, and using it with substantial quantities of ethanol may increase that risk.

Olopatadine is present in breast milk.

Concentrations of Olopatadine in breast milk increase with supplementation. When used as a dietary supplement, the recommended dietary allowance of Olopatadine is increased in breastfeeding patients compared to nonbreastfeeding patients. Doses of Olopatadine for the treatment of dyslipidemias are greater than those used as a dietary supplement. Due to the potential for serious adverse reactions in the breastfed infant (including hepatoxicity), the manufacturer recommends that breastfeeding be discontinued when Olopatadine is used for treatment of dyslipidemias.

There are no known food interactions with olopatadine. However, it is recommended to avoid drinking alcohol while taking olopatadine, as it can increase the risk of drowsiness and dizziness.

• Common Adverse effects

Eye irritation or burning (when used as eye drops), Headache ,Taste disturbances, Dry mouth, Fatigue or drowsiness, Dizziness, Nausea

• Less Common Adverse effects

Cardiovascular effects such as increased heart rate, palpitations, and high blood pressure.

Respiratory effects such as thickening of bronchial secretions, which can make it difficult to breathe, especially in patients with asthma or COPD.

Skin reactions such as rash, hives, and itching.

Allergic reactions such as anaphylaxis, which is a severe and potentially life-threatening allergic reaction.

Gastrointestinal effects such as abdominal pain and diarrhea.

Fatigue, weakness, and headache.

• Rare Adverse effects

Allergic reactions: In rare cases, Olopatadine may cause an allergic reaction, which can be life-threatening. Symptoms of an allergic reaction may include difficulty breathing, swelling of the face, lips, tongue or throat, or a skin rash.

Liver injury: There have been rare reports of liver injury associated with the use of Olopatadine, including cases of hepatitis and elevated liver enzymes.

Seizures: Olopatadine may lower the seizure threshold in some people, especially those with a history of seizures or epilepsy.

Cardiac events: There have been rare reports of cardiac events associated with the use of Olopatadine, including tachycardia, palpitations, and QT prolongation.

There are no known significant drug interactions with olopatadine. However, it is always important to inform a healthcare provider of all medications, supplements, and vitamins being taken, as some medications may interact with olopatadine and alter its effectiveness or increase the risk of side effects.

The common side effects of Olopatadine include the following :

Eye irritation or burning (when used as eye drops), Headache, Taste disturbances, Dry mouth, Fatigue or drowsiness, Dizziness and Nausea.

There is limited information on the effects of over dosage with olopatadine. However, taking more than the recommended dose of olopatadine can increase the risk of side effects, such as drowsiness, dizziness, headache, dry mouth, or nausea.

If an overdose is suspected, it is important to seek immediate medical attention. Treatment may involve supportive care to manage symptoms, such as monitoring vital signs, providing oxygen, or administering fluids. In severe cases, activated charcoal or other interventions may be used to reduce the absorption of the medication.

Pharmacodynamic

Olopatadine is a selective antagonist of histamine H1-receptors. Histamine is a substance that is released in the body during an allergic reaction, causing symptoms such as itching, swelling, and redness. By blocking the effects of histamine, olopatadine can reduce the symptoms of allergic reactions.

Pharmacokinetics

• Absorption: Olopatadine is well-absorbed after oral administration, with a bioavailability of approximately 40%. The absolute bioavailability of olopatadine nasal spray is approximately 25%. The bioavailability of olopatadine eye drops is approximately 10% due to first-pass metabolism.

• Distribution: Olopatadine is extensively distributed throughout the body, with a volume of distribution of approximately 20 L/kg. It binds to plasma proteins at a rate of approximately 60%.

• Metabolism: Olopatadine undergoes extensive metabolism in the liver, primarily by the cytochrome P450 (CYP) 3A4 enzyme. The major metabolite of olopatadine is desmethyl olopatadine, which is also active and has a similar pharmacologic profile.

• Excretion: Olopatadine and its metabolites are excreted primarily in the urine (approximately 60%) and feces (approximately 20%) over 24 hours. The elimination half-life of olopatadine is approximately 3-4 hours.

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1364710/
2. https://reference.medscape.com/drug/colestid-Olopatadine -342452
3. https://go.drugbank.com/drugs/DB00375
4. https://www.sciencedirect.com/topics/medicine-and-dentistry/Olopatadine
5. https://europepmc.org/article/med/6988203