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Class: Antiallergic Agents
- Histamine H1-receptor Antagonists
- Mast-cell Stabilizers
ATC Class: S01GX08
VA Class: OP900
Chemical Name: 10H-Benzo(4,5)cyclohepta(1,2-b)thiophen-10-one,4,9-dihydro-4-(1-methyl-4-piperidinylidene)
Molecular Formula: C19H19NOS
CAS Number: 34580-13-7
Brands: Zaditor

Medically reviewed by Last updated on February 19, 2021.


Relatively selective histamine H1-receptor antagonist and mast-cell stabilizer.1

Uses for Ketotifen

Allergic Conjunctivitis

Self-medication for temporary relief of ocular itching associated with allergic conjunctivitis (i.e., conjunctivitis due to pollen, grass, ragweed, or animal hair or dander).6 7

Ketotifen Dosage and Administration


Ophthalmic Administration

Apply topically to the eye as an ophthalmic solution.6 7


Available as ketotifen fumarate; dosage expressed in terms of ketotifen.6 7

Pediatric Patients

Allergic Conjunctivitis

One drop of a 0.025% solution in the affected eye(s) twice daily (at an interval of 8–12 hours) for those ≥3 years of age.6 7


Allergic Conjunctivitis

One drop of a 0.025% solution in the affected eye(s) twice daily (at an interval of 8–12 hours).6 7

Prescribing Limits

Pediatric Patients

Allergic Conjunctivitis

Do not administer more frequently than twice daily.6 7


Allergic Conjunctivitis

Do not administer more frequently than twice daily.6 7

Cautions for Ketotifen


  • Known hypersensitivity to ketotifen or any ingredient in the formulation.6 7


Specific Populations


Category C.1


Distributed into milk in rats following oral administration.1 Cautious use is recommended.1

Pediatric Use

Safety and efficacy not established in children <3 years of age.6 7

Should not be used in children <3 years of age unless otherwise directed by a clinician.6 7

Common Adverse Effects

Conjunctival injection, headaches, rhinitis.1 Some events may be related to the underlying ocular disease.1

Ketotifen Pharmacokinetics



Minimally absorbed following topical application to the eye.1


Within minutes after topical application to the eye.1





4–25°C.6 7

Do not use if solution changes color or becomes cloudy.6 7


  • Suppresses the release of mediators from cells involved in hypersensitivity reactions and decreases chemotaxis and activation of eosinophils.1

Advice to Patients

  • Importance of learning and adhering to proper administration techniques to avoid contamination of the product.6 7

  • Importance of delaying insertion of contact lenses for at least 10 minutes after ketotifen instillation to prevent absorption of benzalkonium chloride by contact lenses.1 6 7

  • Not indicated for contact lens-related irritation.6 7

  • Importance of reporting new-onset eye pain or discomfort, visual disturbances, eye redness, worsening of itching, or itching lasting >72 hours.6 7

  • Importance of seeking quick medical attention if preparation is ingested orally.6 7

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any other concomitant illnesses.6 7

  • Importance of informing patient of other important precautionary information.6 7 (See Cautions.)


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

Ketotifen Fumarate


Dosage Forms


Brand Names




0.025% (of ketotifen)

Alaway (with benzalkonium chloride)

Bausch & Lomb

Zaditor (with benzalkonium chloride)


AHFS DI Essentials™. © Copyright 2021, Selected Revisions March 1, 2008. American Society of Health-System Pharmacists, Inc., 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814.


1. Novartis Opthalmics. Zaditor (ketotifen fumarate) ophthalmic solution prescribing information. Duluth, GA; 2002 Oct.

2. Ciprandi G, Buscaglia S, Cerqueti PM et al. Drug treatment of allergic conjunctivitis: a review of the evidence. Drugs. 1992; 43:154-76.

3. Morrow GL, Abbott RL. Conjunctivitis. Am Fam Physician. 1998; 57:735-46.

4. Titi MJ. A critical look at ocular allergy drugs. Am Fam Physician. 1996; 53:2637-42.

5. Galindez OA, Kaufman HE. Coping with the itchy-burnies: the management of allergic conjunctivitis. Ophthalmology. 1996; 103:1335-6.

6. Novartis. Zaditor (ketotifen fumarate) drug facts. 2007. From Zaditor website ( Accessed 2007 Sep 26.

7. Bausch & Lomb. Alaway (ketotifen fumarate ) ophthalmic solution 0.025%: antihistamine eye drops. From Bausch & Lomb website ( Accessed 2007 Sep 27.