Ethifen

Oral Formulations (Tablet/Syrup):

Approved Uses:

• Prophylaxis of bronchial asthma: As maintenance therapy to reduce asthma attack frequency (not effective for acute asthma attacks).
• Allergic rhinitis: Treatment of seasonal or perennial allergic rhinitis.
• Chronic allergic disorders: Including atopic dermatitis, urticaria, and allergic conjunctivitis.

Ophthalmic Form (Eye Drops 0.025%):

Approved Uses:

• Allergic conjunctivitis: Prevention and relief of ocular itching and irritation due to allergens such as pollen, dust, or animal dander.
• Vernal keratoconjunctivitis: Management of chronic ocular allergies.

Clinically Accepted Off-Label Uses:

• Systemic mastocytosis (oral form): As a mast cell stabilizer.
• Eosinophilic bronchitis and atopic dermatitis: As adjunct therapy.

রেজিস্টার্ড চিকিৎসকের পরামর্শ অনুযায়ী ঔষধ সেবন করুন।

Oral Administration:

• Adults and children ≥3 years:
  1 mg twice daily with food.
  To minimize drowsiness, start with 0.5 mg twice daily for the first few days if needed.
  Maximum dose: 2 mg twice daily.
• Children 6 months to 3 years:
  0.05 mg/kg twice daily (use syrup).
  Example: 0.25 mL/kg of 1 mg/5 mL syrup twice daily.
• Children <6 months:
  Not recommended due to insufficient safety data.

Ophthalmic Administration (0.025% solution):

• Adults and children ≥3 years:
  Instill 1 drop into the affected eye(s) twice daily (morning and evening).
  Treatment may continue throughout allergy season or as directed.

Special Populations:

• Elderly: Same as adult dosage. Monitor for increased sedation.
• Renal impairment: Use with caution; dose reduction may be necessary in severe cases.
• Hepatic impairment: Use with caution; monitor for drug accumulation with long-term use.

রেজিস্টার্ড চিকিৎসকের পরামর্শ অনুযায়ী ঔষধ সেবন করুন।

Ketotifen Fumarate is a non-competitive histamine H1 receptor antagonist and mast cell stabilizer. It inhibits the release of inflammatory mediators such as histamine, leukotrienes, and prostaglandins from mast cells. Additionally, it suppresses eosinophil activation and chemotaxis. These actions help prevent the early and late-phase allergic response in both systemic and ocular tissues, effectively reducing symptoms such as itching, sneezing, wheezing, and inflammation.

• Absorption: Well absorbed after oral administration; peak plasma levels in 2–4 hours.
• Bioavailability: Approximately 50% due to first-pass metabolism.
• Distribution: Wide distribution in tissues; crosses the blood-brain barrier.
• Protein Binding: ~75%
• Metabolism: Hepatic metabolism, primarily via CYP3A4.
• Half-life: 12–14 hours in adults; up to 20 hours in children.
• Excretion: Mostly via the kidneys as metabolites; <2% unchanged drug in urine.

Pregnancy:

• FDA Category C
  Use only if clearly needed. No adequate human studies; animal studies show potential risk. Avoid during the first trimester unless benefits outweigh risks.

Lactation:

• Ketotifen is excreted into breast milk in small amounts.
  Use with caution in breastfeeding mothers. Avoid prolonged use, especially in newborns or preterm infants.

• Primary Class: Antihistamine
• Subclass: Non-competitive H1-receptor antagonist with mast cell stabilizing activity
• Ophthalmic Class: Anti-allergic agent for ocular use

• Known hypersensitivity to Ketotifen or any component of the formulation
• Concomitant use with oral antidiabetic medications (risk of thrombocytopenia)
• Infants under 6 months of age (oral use)

• Sedation: Drowsiness is common, especially at the start of treatment. Caution when driving or operating machinery.
• CNS Depression: May be enhanced with alcohol or other CNS depressants.
• Not for acute asthma attacks: Should be used as a prophylactic agent only.
• Pediatric Use: Monitor closely in children for hyperexcitability or sedation.
• Ophthalmic Precautions: Remove contact lenses before use and wait at least 10 minutes before reinsertion.

Oral Form:

Common:

• Drowsiness, sedation (usually transient)
• Increased appetite
• Weight gain
• Dry mouth
• Dizziness

Less Common:

• Nausea, vomiting, abdominal discomfort
• Irritability or nervousness (mainly in children)

Rare but Serious:

• Seizures
• Hepatic dysfunction
• Thrombocytopenia (especially with oral antidiabetics)

Ophthalmic Form:

Common:

• Transient eye irritation or burning
• Conjunctival redness
• Dry eyes
• Blurred vision

Rare:

• Allergic reaction at the application site
• Eyelid swelling

• CNS depressants (e.g., alcohol, sedatives): May increase sedation.
• Oral antidiabetics (e.g., sulfonylureas): Potential risk of thrombocytopenia; avoid combination.
• MAO inhibitors and tricyclic antidepressants: May enhance sedative effects.
• CYP3A4 inducers (e.g., rifampin, carbamazepine): May reduce ketotifen levels.

• Global allergy and asthma guidelines continue to recommend ketotifen for allergic rhinitis and asthma prophylaxis, especially in pediatric populations.
• Ophthalmic formulations are now available preservative-free in some regions to reduce ocular irritation.
• EMA and WHO maintain ketotifen on the list of approved non-steroidal agents for allergic conjunctivitis and seasonal allergy prevention.

Tablets Oral /Syrup:

• Store below 25°C
• Protect from light and moisture
• Keep out of reach of children

Ophthalmic Solution:

• Store at 2°C to 25°C
• Do not freeze
• Use within 4 weeks after opening the bottle
• Keep the dropper cap tightly closed to avoid contamination