PDR MEMBER LOGIN:
  • PDR Search

    Required field
  • Advertisement
  • CLASSES

    Ocular Anti-Allergics, Antihistamines

    DEA CLASS

    OTC, Rx

    DESCRIPTION

    Ophthalmic antihistamine and mast cell stabilizer; provides temporary relief of allergic conjunctivitis; comparable efficacy to cromolyn ophthalmic solution. Prescription strength ketotifen will be available OTC in Jan. 2007.

    COMMON BRAND NAMES

    Alaway, Children's Alaway, Claritin Eye, Eye Itch Relief, Itchy Eye, Zaditor, Zyrtec Itchy Eye

    HOW SUPPLIED

    Alaway/Children's Alaway/Claritin Eye/Eye Itch Relief/Itchy Eye/Ketotifen/Zaditor/Zyrtec Itchy Eye Ophthalmic Sol: 0.025%

    DOSAGE & INDICATIONS

    For the temporary prevention of ocular pruritus due to allergic conjunctivitis.
    Ophthalmic dosage
    Adults, Adolescents, and Children >= 3 years

    One drop in the affected eye(s) every 8—12 hours.

    For the treatment of allergic conditions including allergic rhinitis†, atopic dermatitis†, and acute or chronic urticaria†.
    Oral dosage†

    NOTE: Oral formulation is not available in the US

    Adults, Adolescents, and Children > 3 years

    1 mg PO every 12 hours. Ketotifen is also available in a sustained release oral formulation that allows for once daily dosing. If excessive sedation is a problem, treatment should be initiated at one-half the normal dose or the drug should be given at bedtime.

    Infants > 6 months and Children <= 3 years

    0.5 mg PO every 12 hours.

    †Indicates off-label use

    MAXIMUM DOSAGE

    Adults

    3 drops/day ophthalmic solution in each affected eye.

    Elderly

    3 drops/day ophthalmic solution in each affected eye.

    Adolescents

    3 drops/day ophthalmic solution each affected eye.

    Children

    >= 3 years: 3 drops/day ophthalmic solution in each affected eye. 
    < 3 years: Safety and efficacy have not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    No dosage adjustments are needed for the ophthalmic product.

    Renal Impairment

    No dosage adjustments are needed for the ophthalmic product.

    ADMINISTRATION

    Oral Administration

    NOTE: Oral formulation is not available in the US
    Ketotifen may be given orally without regard to meals.
    Lower oral dosage, or the administration of the oral dosage at bedtime, may be needed in patients who experience excessive sedation during the first 2 weeks of treatment.
    Ketotifen is available in other countries besides the US as a tablet and oral syrup formulation.

    Ophthalmic Administration

    Ketotifen is for topical ophthalmic use only. Do not give by injection or orally.
    Wash hands before and after use. Tilt the head back slightly and pull the lower eyelid down with the index finger. Squeeze a drop into the conjunctival sac and gently close the eye and apply pressure for 1 to 2 minutes over the point where the lid meets the nose. If more than one drop it to be administered, wait 3 to 4 minutes before instilling another drop into the same eye.
    Care should be taken to avoid contamination. Do not touch the tip of the dropper to the eye, fingertips, or other surface.
    If multiple ophthalmic medications are to be administered, wait at least 5 to 15 minutes before delivering a second medication to the same eye to prevent dilution.
    Patients should wait at least 10 minutes after instilling the ophthalmic solution before inserting contact lenses.
    Do not share ophthalmic drops between patients.

    STORAGE

    Alaway:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Children's Alaway:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Claritin Eye:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Eye Itch Relief:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Itchy Eye:
    - Store at controlled room temperature (between 68 and 77 degrees F)
    Zaditor:
    - Store between 39 to 77 degrees F
    Zyrtec Itchy Eye :
    - Store at controlled room temperature (between 68 and 77 degrees F)

    CONTRAINDICATIONS / PRECAUTIONS

    Children, infants, neonates

    Safe and effective use of ocular ketotifen in neonates, infants, and children below the age of 3 years has not been established. Oral ketotifen has been given to children as young as 6 months at dosages one-half the usual adult dose.

    Contact lenses

    The preservative benzalkonium chloride may be absorbed by soft contact lenses. Contact lens wearers should wait at least 10 minutes after using ketotifen before inserting their lenses. Do not use ketotifen to treat contact lens related ocular irritation.

    Pregnancy

    Ocular ketotifen is considered a FDA pregnancy category C agent. Animal data reveal no harmful effects of ketotifen during pregnancy.No adequate and well-controlled studies of ketotifen in pregnant women have been performed. Ketotifen has been shown to have little systemic exposure following ocular administration, even with repeat dosing. Thus, harmful effects during pregnancy would not be expected. It is recommended that pregnant women check with their qualified health care professional prior to self-treatment with any medicine, including this non-prescription antihistamine eye drop.

    Breast-feeding

    Caution should be exercised when systemically administered ketotifen is administered to a women who is breast-feeding. Ketotifen has been identified in breast milk in animals following oral administration. Ketotifen ophthalmic solution has been shown to have little systemic exposure following ocular administration, even with repeat dosing ; thus ocular administration is not likely to produce detectable quantities in breast milk.

    DRUG INTERACTIONS

    There are no drug interactions associated with Ketotifen products.

    PREGNANCY AND LACTATION

    Pregnancy

    Ocular ketotifen is considered a FDA pregnancy category C agent. Animal data reveal no harmful effects of ketotifen during pregnancy.No adequate and well-controlled studies of ketotifen in pregnant women have been performed. Ketotifen has been shown to have little systemic exposure following ocular administration, even with repeat dosing. Thus, harmful effects during pregnancy would not be expected. It is recommended that pregnant women check with their qualified health care professional prior to self-treatment with any medicine, including this non-prescription antihistamine eye drop.

    Caution should be exercised when systemically administered ketotifen is administered to a women who is breast-feeding. Ketotifen has been identified in breast milk in animals following oral administration. Ketotifen ophthalmic solution has been shown to have little systemic exposure following ocular administration, even with repeat dosing ; thus ocular administration is not likely to produce detectable quantities in breast milk.

    MECHANISM OF ACTION

    Ketotifen is a relatively selective, non-competitive H1-antagonist and mast cell stabilizer. Ketotifen effects several interdependent pathways that mediate asthma and anaphylaxis including calcium fluxes in excitable cells, production and release of mediators of hypersensitivity and inflammation, smooth-muscle contractility, and the density and sensitivity of adrenergic receptors. Decreased chemotaxis and activation of eosinophils has also been demonstrated. In patients with HIV, ketotifen has been shown to decrease tumor necrosis factor secretion, which has lead to study of ketotifen in wasting syndromes associated with HIV.

    PHARMACOKINETICS

    Ketotifen may be administered orally or topically to the eye; however, only the topical ophthalmic preparation is available in the US.  Ketotifen is 75% bound to plasma proteins. Ketotifen undergoes glucuronidation to the inactive metabolite ketotifen-N-glucuronide and demethylation to nor-ketotifen, which has similar activity as the parent compound. The distribution and elimination half-lives following oral administration of ketotifen are 2 and 22 hours, respectively. About 60—70% of ketotifen, primarily as the N-glucuronide metabolite, is eliminated in the urine with in 48 hours.

    Oral Route

    Following oral administration, ketotifen is completely absorbed but the absolute bioavailability is only 50% due to extensive first pass metabolism.

    Other Route(s)

    Ophthalmic Route
    Following ophthalmic administration, the onset of action of ketotifen is within minutes. Ketotifen has been shown to have little systemic exposure following ocular administration. In healthy volunteers treated with ketotifen for 14 days, plasma concentrations were generally below the quantation limit of the assay (< 20 pg/mL).