Ketotifen is a second-generation antihistamine and mast cell stabilizer used primarily for the prophylactic management of allergic conditions, including allergic conjunctivitis, allergic rhinitis, and certain forms of asthma and urticaria. It functions by inhibiting the release of inflammatory mediators from mast cells, thereby reducing hypersensitivity reactions and providing long-term control over allergic symptoms. Available in oral and ophthalmic formulations, ketotifen offers a dual mechanism of action that distinguishes it from conventional antihistamines, making it a valuable option for patients requiring sustained allergic symptom control.

Features

• Contains ketotifen fumarate as the active pharmaceutical ingredient
• Available in oral syrup, tablet, and ophthalmic solution formulations
• Exhibits both potent H1-receptor antagonism and mast cell stabilizing properties
• Rapid onset of action with symptomatic relief often observed within hours
• Suitable for both pediatric and adult populations (age-specific formulations)
• Long duration of effect allowing for convenient twice-daily dosing in most cases

Benefits

• Provides prophylactic protection against allergic triggers by stabilizing mast cells and preventing degranulation
• Reduces the frequency and severity of allergic asthma attacks and bronchospasm
• Alleviates ocular symptoms such as itching, redness, and watering in allergic conjunctivitis
• Minimizes nasal congestion, sneezing, and rhinorrhea associated with allergic rhinitis
• Offers a favorable safety profile with minimal sedative effects compared to first-generation antihistamines
• Supports long-term management of chronic urticaria and atopic dermatitis

Common use

Ketotifen is commonly prescribed for the prevention and treatment of various allergic disorders. Its primary indications include perennial and seasonal allergic rhinitis, allergic conjunctivitis, mild to moderate allergic asthma, and chronic idiopathic urticaria. It is also used off-label in the management of mast cell activation syndrome (MCAS), eosinophilic esophagitis, and certain food allergy-related symptoms. In ophthalmology, ketotifen eye drops are widely utilized for immediate and prolonged relief from ocular allergy symptoms.

Dosage and direction

Oral administration (tablets/syrup):

• Adults and children over 3 years: 1 mg twice daily; may be increased to 2 mg twice daily in severe cases.
• Maintenance dose should be individualized based on clinical response.

Ophthalmic solution:

• Instill one drop into the affected eye(s) every 8–12 hours.

Take oral ketotifen with or without food. Consistency in timing is advised to maintain stable plasma concentrations. Do not discontinue abruptly without medical consultation.

Precautions

• Use with caution in patients with renal or hepatic impairment; dose adjustment may be necessary.
• May cause drowsiness, especially during initial therapy; avoid driving or operating machinery until response is known.
• Not recommended during pregnancy unless potential benefits outweigh risks (Category C).
• Exercise caution in elderly patients due to potential increased sensitivity to side effects.
• Monitor for signs of infection, as immunosuppressive effects are theoretically possible.

Contraindications

• Hypersensitivity to ketotifen or any component of the formulation.
• Acute asthmatic attack or status asthmaticus (not for rescue use).
• Neonates and infants under 3 years of age for oral formulations.
• Concomitant use with monoamine oxidase inhibitors (MAOIs).

Possible side effect

Common side effects include:

• Drowsiness, sedation
• Dry mouth, nausea
• Weight gain
• Dizziness, headache

Less frequently reported:

• irritability, nervousness
• thrombocytopenia
• elevated liver enzymes
• blurred vision (ophthalmic formulation)

Drug interaction

• CNS depressants (e.g., alcohol, benzodiazepines): enhanced sedative effect.
• MAOIs: risk of hypertensive crisis.
• Anticholinergic drugs: may enhance dry mouth or urinary retention.
• Theophylline: ketotifen may increase theophylline levels.
• Oral hypoglycemics: potential alteration in glucose metabolism.

Missed dose

If a dose is missed, take it as soon as remembered. If it is near the time of the next dose, skip the missed dose and resume the regular schedule. Do not double the dose.

Overdose

Symptoms may include severe drowsiness, confusion, tachycardia, hypotension, or seizures. Gastric lavage and symptomatic supportive care are recommended. There is no specific antidote.

Storage

Store at room temperature (15–30°C), away from light and moisture. Keep out of reach of children. Do not use after the expiration date.

Disclaimer

This information is for educational purposes and does not replace professional medical advice. Always consult a healthcare provider for diagnosis, treatment decisions, and personalized dosage recommendations.

Reviews

“Ketotifen has been transformative for my chronic urticaria. After years of trying different antihistamines, this provided consistent relief without significant drowsiness.” – Maria L., 42

“As an allergist, I find ketotifen particularly useful for pediatric patients with multi-system allergic symptoms. Its mast cell stabilizing action offers a mechanistic advantage.” – Dr. A. Reynolds, MD