You should talk with your healthcare provider prior to taking this medication if you:
- Have any allergies, including allergies to food, dyes, or preservatives
- Are pregnant or thinking of becoming pregnant (see Ketotifen and Pregnancy)
- Are breastfeeding (see Ketotifen and Breastfeeding).
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Precautions and Warnings With Ketotifen to learn more, including information on who should not take the drug.)
Ketotifen belongs to a group of allergy medications known as antihistamines. Specifically, it is an H1 receptor antagonist. This means that it blocks a specific type of histamine receptor in the body (known as H1 receptors). Since the symptoms of allergic reactions are partly caused by histamine, ketotifen can help prevent or relieve allergy symptoms.
In addition to blocking histamine receptors, this medication also seems to decrease the release of histamine from cells in the body and may also inhibit other substances (such as leukotrienes or eosinophils) produced by the body in response to an allergen.