In this drug factsheet:
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people using this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if your child experiences these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- abdominal pain
- dry mouth
- increased appetite
- sleep disturbances (e.g., trouble sleeping)
- slight dizziness
- weight gain
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- flu-like symptoms (e.g., sudden lack of energy, fever, cough, sore throat)
- puffy eyelid(s)
- respiratory infections
- skin rashes and itching
Stop using the medication and seek immediate medical attention if any of the following occur:
- signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are using this medication.
Are there any other precautions or warnings for this medication?
Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Diabetes: If you have diabetes, you should be aware that the syrup form of this medication contains 4 g of carbohydrates per 5 mL of syrup. There have also been rare reports of decreased blood cell counts in people taking antidiabetes medications and ketotifen at the same time. Talk to your doctor if you have any concerns.
Drowsiness/reduced alertness: This medication may cause drowsiness. Parents and guardians should be aware that children may experience drowsiness in the early stages of therapy. They should not perform potentially hazardous tasks until you have determined how this medication affects them.
Other asthma medications: Medications used to treat and prevent asthma (e.g., b2-agonists such as salbutamol; sodium cromoglycate; corticosteroids such as beclomethasone, budesonide, and fluticasone) already in use should not be reduced immediately when treatment with ketotifen is started. Follow your doctor's instructions closely.
Seizure: Ketotifen may increase the risk of seizures, particularly if your child has a history of seizures. If you or your child have seizures or a history of seizures, discuss with your doctor how this medication may affect this medical condition, how this medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Pregnancy and breast-feeding: Ketotifen should not be used by anyone who is pregnant or breast-feeding.
What other drugs could interact with this medication?
There may be an interaction between ketotifen and any of the following:
- antidiabetes medications (e.g., glyburide, metformin)
- medications that cause drowsiness (e.g. sleeping pills, antihistamines, alcohol)
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.