Some commonly used brand names are:
- Asthma prophylactic, systemic
- Antiallergic, systemic
Ketotifen (kee-toe-TYE-fen) is a type of asthma medication which, when taken every day and used along with other antiasthma medications, may reduce the frequency, severity, and duration of asthma symptoms or attacks in children. It may also lead to a reduction in daily requirements of other antiasthma medications. Ketotifen is not effective for the prevention or treatment of acute asthma attacks. Ketotifen works by inhibiting certain substances in the body that are known to cause inflammation and symptoms of asthma.
This medicine is available only with your doctor's prescription, in the following dosage forms:
- Syrup (Canada)
- Tablets (Canada)
Before Using This Medicine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For ketotifen, the following should be considered:
Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to ketotifen. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.
Pregnancy—Ketotifen has not been studied in pregnant women. However, studies in animals have shown that ketotifen crosses the placenta and, at high doses, cause problems. Before using this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.
Breast-feeding—It is not known whether ketotifen passes into human breast milk. However, it does pass into the milk of rats. It may be necessary for you to take another medicine or to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of the medicine with your doctor.
Children— This medicine has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults.
Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of ketotifen in the elderly with use in other age groups.
Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking ketotifen, it is especially important that your health care professional knows if you are taking any of the following:
- Antidiabetic agents, oral—May increase the risk of bruising or bleeding and affect blood sugar concentrations
- Alcohol or
- Antihistamines or
- Hypnotics or
- Sedatives—May increase the chance of side effects (i.e., drowsiness)
Other medical problems—The presence of other medical problems may affect the use of ketotifen. Make sure you tell your doctor if you have any other medical problems, especially:
- Diabetes mellitus (sugar diabetes)—May alter low-sugar diet (syrup contains carbohydrates)
- Epilepsy—May increase risk of convulsions (seizures)
Proper Use of This Medicine
Make certain your health care professional knows if you are on any special diet, such as a low-sugar diet. The syrup contains carbohydrates.
Ketotifen is used to help prevent asthma attacks. It will not relieve an asthma attack that has already started .
Ketotifen must be taken continuously in order to be effective.
Continue taking your current asthma medications until instructed otherwise by your doctor.
Ketotifen may be taken with or without food.
Dosing—The dose of ketotifen will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only the average doses of ketotifen. If your dose is different, do not change it unless your doctor tells you to do so.
- For oral dosage form (tablets and syrup):
- For asthma:
- Adults and children 3 years of age and older—The usual dose is 1 milligram (mg) (1 tablet or 5 milliliters [mL] of syrup) twice daily, once in the morning and once in the evening.
- Infants and children from 6 months to 3 years of age—Dose is based on body weight and must be determined by the doctor. It is usually 0.25 mL (50 mcg or 0.05 mg) of syrup per kilogram (kg) (110 micrograms [mcg] or 0.110 mg per pound) of body weight twice daily, once in the morning and once in the evening.
- For asthma:
Missed dose—If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Storage—To store this medicine:
- Keep out of the reach of children.
- Do not store tablets in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
- Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.
Precautions While Using This Medicine
It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. If your symptoms worsen, you should check with your doctor.
This medicine may cause some people to become drowsy, dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert .
This medicine may cause some people to become excited, irritable, or nervous or to have trouble in sleeping . These are symptoms of central nervous system stimulation and are especially likely to occur in children.
For patients with diabetes :
- The syrup form of this medicine may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.
Side Effects of This Medicine
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Chills; cough; diarrhea; fever; general feeling of discomfort or illness; headache; joint pain; loss of appetite; muscle aches and pains; nausea; runny nose; shivering; sore throat; sweating; trouble sleeping; unusual tiredness or weakness; vomiting
Abdominal or stomach pain; blistering, itching, peeling, or redness of skin; bloody or cloudy urine; clay-colored stools; convulsions; dark urine; difficult, burning, or painful urination; dizziness; frequent urge to urinate; muscle spasm or jerking of all extremities; rash; sudden loss of consciousness; unpleasant breath odor; vomiting of blood; yellow eyes or skin
Symptoms of overdose
Get emergency help immediately if any of the following symptoms of overdose occur
Blurred vision; confusion; convulsions; disorientation; dizziness; drowsiness (severe); faintness or lightheadedness when getting up from a lying or sitting position; fast, pounding, or irregular heartbeat or pulse; hyperexcitability; loss of consciousness; palpitations; sweating; unusual tiredness or weakness
Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome.
Less common or rare
Bloody nose; drowsiness; dryness of mouth; excitation; increased appetite; irritability; nervousness; swelling of eyelids; unexplained nosebleeds
Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.