Zaditen® syrup   

This product is manufactured by Teva Pharmaceutical Industries using the ingredient ketotifen.

This product is taken orally.


Why is it prescribed?

Ketotifen is used as an add-on medication in the long term treatment of mild allergic asthma in children.

  • Zaditen® syrup is intended to be used on a regular basis to prevent asthma symptoms. It is not a bronchodilator and is of no use as a rescue medication in an acute asthmatic episode.
  • Keep a diary of the time, frequency, and severity of your child's asthma episodes for the first three months after starting Zaditen®. This will help your doctor assess how well your child is responding to the new medication and will assist him/her in adjusting the therapy for maximum benefit.
  • Do not stop using Zaditen® or change the dosage without first consulting your doctor. Sudden withdrawal of the medication may cause an unexpected return of asthma symptoms.
  • Zaditen® syrup contains benzoates and should not be used by people with benzoate allergies.
  • The effect of Zaditen® syrup is not influenced by the intake of food and can be taken without regard to meals.
  • Zaditen® syrup should be stored at temperatures not exceeding 25 degrees centigrade.


Other products that have the same ingredient as Zaditen® syrup are •Zaditen® tablets •

See other products used in the treatment of •asthma •

The recommended dosage for children older than 3 years of age is 1 mg twice daily, in the morning and evening. For children aged 6 months to 3 years old, the recommended dose is 0.05mg per kilogram of body weight given twice daily in the morning and evening. To minimize the initial sedation with Zaditen®, a slow increase in dosage is recommended during the first week of treatment. Treatment may be started with one-half the recommended daily dosage given in two divided doses or in a single dose given in the evening, followed by an increase to the full recommended dosage within 5 days.

Ketotifen is a drug that blocks the release of various chemical messengers in the body that are responsible for producing the symptoms of an asthma episode after a person has been exposed to an allergy producing substance. Ketotifen also works as an antihistamine by blocking the activity of histamine at the body's histamine receptors. By blocking the release of these allergic chemical messengers and by blocking the effect of histamine, ketotifen can prevent the bronchoconstriction and obstructed airways associated with an asthmatic episode. Ketotifen is not a bronchodilator.

Along with its needed effects, ketotifen may cause some unwanted or undesirable effects. Generally, ketotifen is well tolerated and many people will not experience unwanted effects. Possible unwanted effects include:

  • sedation
  • weight gain
  • increased appetite
  • rash
  • respiratory infections


  • sleep disturbance
  • headache


It is important that ketotifen users understand that this medication is not a bronchodilator and should not be used as a rescue medication in acute asthmatic episodes.
Ketotifen will only work properly if it is taken on a regular basis. Sporadic use, or only using the medication when experiencing symptoms, will lead to poor symptom control.
Don't expect ketotifen to start working immediately when therapy is started. Improvement may be seen in the first few weeks of starting the medication, but it may take 10 weeks before any significant improvement can be detected.
Never stop using ketotifen abruptly, especially if symptoms have been partially or completely controlled by the medication. Do not adjust your dosage or discontinue ketotifen without the advise of your doctor.
Drowsiness may occur in the early stages of treatment. This effect often disappears with continued use, but caution should be used when preforming activities requiring rapid and precise responses.
Drug Interactions: Ketotifen has relatively few drug interactions, but it is important to inform your doctor and pharmacist of all the prescription and over-the-counter medications your child is taking. Problems have occurred with the following:

  • oral antidiabetic medications
  • medications with a sedating effect

Use is not recommended in the following situations:

  • allergy to ketotifen
  • people sensitive to benzoate compounds should not take ketotifen syrup

Use in pregnancy: Safety for use in pregnancy has not yet been established. If you suspect that you might be pregnant, consult your doctor.

Use while breastfeeding: Ketotifen is passed into breast milk. Consult your doctor or pharmacist before use.

Page Last Updated: 05/10/2016