Ketotifene
Ketotifene Uses, Dosage, Side Effects, Food Interaction and all others data.
Ketotifene is a potent anti-allergic substance possessing a powerful and sustained non-competitive histamine (H1) receptor blocking property. Ketotifene inhibits the release of mediators (e.g histamine, leukotrienes and prostaglandins) from cells responsible for type-(I) allergic reactions. Ketotifene also stabilizes mast cells, decreases chemotaxis, activation of degranulation of eosinophils. Also, it stabilizes mast cells & basophils and inhibits PAF (platelet activating factor) and is effective in preventing asthmatic attacks.
Ketotifene is a non-competitive histamine antagonist and mast cell stabilizer. Administered orally, it functions as a non-bronchodilator antiasthmatic drug by inhibiting the effects of endogenous substances known to be inflammatory mediators. While effects can take 6 to 12 weeks to become apparent, the use of ketotifen has been demonstrated to reduce the frequency, severity, and duration of asthma symptoms, and may allow for a reduction in the use of other asthma therapies.
| Trade Name | Ketotifene |
| Availability | Over the counter |
| Generic | Ketotifen |
| Ketotifen Other Names | Ketotifen, Ketotifene, Ketotifeno, Ketotifenum |
| Related Drugs | prednisone, cetirizine ophthalmic, dexamethasone ophthalmic, prednisolone ophthalmic, azelastine ophthalmic, doxylamine |
| Type | |
| Formula | C19H19NOS |
| Weight | Average: 309.425 Monoisotopic: 309.118734925 |
| Protein binding | Ketotifen is 75% protein-bound in plasma, though the specific proteins to which it binds are unclear. |
| Groups | Approved |
| Therapeutic Class | Cromoglycate & related drugs |
| Manufacturer | |
| Available Country | |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Ketotifene is used for the prophylactic treatment of bronchial asthma, symptomatic treatment of allergic conditions including rhinitis and conjunctivitis.
Ketotifene has antiallergic properties and has been used similarly, to Sodium Chromoglycate in the prophylactic treatment of asthma. It also has the properties of an antihistamine. Ketotifene possesses marked anti-anaphylactic properties and is effective in preventing asthmatic attack. Ketotifene exerts sustained inhibitory effect on histamine reactions, which can be clearly dissociated from its antianaphylactic properties. Experimental investigations in asthmatic subjects have shown that Ketotifene is as effective orally as administered by inhalation as a selective mast cell stabiliser. Antihistamines were ineffective in those tests. The effectiveness of Ketotifene has been studied in long term clinical trials. Asthma attacks were reduced in number, severity and duration and in some cases, the patients were completely freed from attacks. Progressive reduction of corticosteroids and/or bronchodilators was also possible. The prophylactic activity of Ketotifene may take several weeks to become fully established. Ketotifene will not abort established attacks of asthma.
Ketotifene eye drop is used for the treatment of signs & symptoms (itchy, watery, red & swollen eyes and eyelids) of allergic conjunctivitis including vernal kerato-conjunctivitis, vernal-keratitis, blepharitis, blepharo-conjunctivitis, and giant papillary conjunctivitis.
Ketotifene is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Asthma, Allergic, Eye pruritus, Seasonal Allergic Conjunctivitis
How Ketotifene works
The precise mechanism(s) through which ketotifen exerts its therapeutic effects are unclear. Ketotifene is a potent and non-competitive antagonist of H1 histamine receptors, which is likely to be a significant contributor to its anti-allergic activity. In addition, ketotifen stabilizes mast cells and has demonstrated in vitro the ability to inhibit the release of allergic and inflammatory mediators such as histamine, leukotrienes C4 and D4 (i.e. SRS-A), and platelet-activating factor (PAF).
Other in vivo observations thought to contribute to ketotifen's efficacy in asthma include the inhibition of various PAF-mediated processes (e.g. airway hyperreactivity, eosinophil and platelet accumulation in the airways), prevention of leukotriene-induced bronchoconstriction, and suppression of eosinophil priming.
Dosage
Ketotifene dosage
Adults: 1 mg twice daily with food. If necessary the dose may be increased to 2 mg twice daily in severe cases.
Children above 2 years: 1 mg twice daily with food. Patient’s known to be easily sedated should begin treatment with 0.5 to 1 mg at night for the first few days or as directed by the physician.
Use in elderly: Same as adult dose or as advised by the physician.
Adults and children 3 years and older: 1 drop in the affected eye(s) twice daily, every 8-12 hours, not more than twice per day.
Children under 3 years of age: Consult with a doctor.
Side Effects
Drowsiness and in isolated cases, dry mouth and slight dizziness may occur at the beginning of treatment, but usually disappear spontaneously after a few days.
Common side effects are burning, stinging, punctate corneal epithelial erosion, Blurring of vision upon drug instillation, dry eyes, eyelid disorder, conjunctivitis, eye pain, photophobia, subconjunctival haemorrhage.
Toxicity
Oral ingestion of up to 60x the recommended dose has been reported, although no fatal overdoses of ketotifen have been described. Symptoms of ketotifen overdosage may include significant sedation, confusion, disorientation, tachycardia, hypotension, convulsions, hyperexcitability (particularly in children), and/or reversible coma. If ingestion is recent, consider the use of gastric lavage or activated charcoal. Other treatments should be supportive and administered as necessary based on symptoms.
Physostigmine may be useful to mitigate anticholinergic effects, and short-acting barbiturates or benzodiazepines may be used if the patient presents with excitation or convulsions.
Precaution
It is important to continue the previous treatment for a minimum of two weeks after starting Ketotifene to avoid the possibility of exacerbation of asthma. This applies specially to systemic corticosteroids and ACTH because of the possible existence of adrenocortical insufficiency in steroid dependent patient. If intercurrent infection occurs, Ketotifene treatment must be supplemented by specific antimicrobial therapy. During the first day of treatment with Ketotifene, reactions may be impaired and patients should be warned not to take charge of vehicle or machinery until the effect of Ketotifene treatment on the individual is known. Patient should be advised to avoid alcoholic drinks. Ketotifene may potentiate the effects of sedatives, hypnotic, antihistamines and alcohol.
The formulation of Ketotifene 0.025% eye drops contains benzalkonium chloride as a preservative, which may be deposited in soft contact lenses; therefore this eye drops should not be instilled while the patient is wearing lenses. The lenses should be removed before application of the drops and not reinserted earlier than 15 minutes after use.
Interaction
A reversible fall in the platelet count has been observed in a few patients receiving Ketotifene concomitantly with oral antidiabetics and it has been suggested that this combination should therefore be avoided. Since Ketotifene has the properties of the antihistamines, it may potentiate the effects of other CNS depressant drugs such as alcohol, antihistamines, hypnotics and sedatives.
If Ketotifene eye drops is used concomitantly with other eye medications there must be an interval of at least 5 minutes between the two medications.
Food Interaction
- Take with or without food. The co-administration of food does not significantly affect ketotifen disposition.
Elimination Route
Following oral administration, absorption is relatively quick (with a Tmax of ~3 hours) and nearly complete as judged by plasma concentrations and urinary excretion levels - despite this, oral bioavailability is only ~50% due to a significant first-pass effect in the liver.
Half Life
Ketotifene clearance is biphasic - the half-life of the distribution phase is approximately 3-5 hours and the half-life of the elimination phase is 22 hours.
Elimination Route
More than 60% of an administered dose is excreted in the urine, primarily as metabolites - of this material, 5
Pregnancy & Breastfeeding use
Although there is no evidence of any teratogenic effect, Ketotifene in pregnancy and lactation is not recommended.
Contraindication
A reversible fall in the platelet count has been observed in a few patients receiving Ketotifene concomitantly with oral antidiabetic agent and it has been suggested that this combination should therefore be avoided.
Hypersensitivity to Ketotifene or any of the components
Acute Overdose
Symptoms: Drowsiness, confusion, dyspnoea, bradycardia or tachycardia, disorientation, convulsions, severe hypotension, reversible coma.
Management: Supportive and symptomatic.
No case of overdose has been reported. Oral ingestion of the contents of a 5 ml bottle would be equivalent to 1.25 mg of Ketotifene which is 60% of a recommended oral daily dose for a 3 years old child. Clinical results have shown no serious signs or symptoms after oral ingestion of up to 20 mg of Ketotifene.
Storage Condition
Store at 25° C.
Innovators Monograph
You find simplified version here Ketotifene
Ketotifene contains Ketotifen see full prescribing information from innovator Ketotifene Monograph, Ketotifene MSDS, Ketotifene FDA label
FAQ
What is Ketotifene used for?
Ketotifene ophthalmic (eye) solution is used to temporarily prevent itching of the eye caused by a condition known as allergic conjunctivitis. Ketotifene is also used to help prevent asthma attacks.
How safe is Ketotifene?
Ketotifene is safe for OTC use based on the long-term use of the drug, as well as the controlled clinical studies that supported the original prescription-strength formula.
How does Ketotifene work?
Ketotifene works by preventing inflammation and allergic reactions in your body.
What are the common side effects of Ketotifene?
The common side effects of Ketotifene are Burning/stinging/irritation of the eye, headache, stuffy/runny nose, bad taste in your mouth, and increased sensitivity to light. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Is Ketotifene safe during pregnancy?
Animal data reveal no harmful effects of Ketotifene during pregnancy.No adequate and well-controlled studies of Ketotifene in pregnant women have been performed.
Is Ketotifene safe during breastfeeding?
Because absorption from the eye is limited, Ketotifene would not be expected to cause any adverse effects in breastfed infants after maternal use of ketotifen eye drops.
Can I drink alcohol with Ketotifene?
Ketotifene it is best not to drink alcohol while you are on Ketotifene. If you are having an operation or any treatment (particularly if it is to test for an allergy), tell the person carrying out the treatment that you are taking an antihistamine.
Can I take Ketotifene for a long time?
Ketotifene may be taken with or without food.
How much can I take Ketotifene daily?
The usual recommended doses are: Adults: one tablet (1 mg) twice daily. Children aged over 3 years: one 5 ml spoonful (1 mg) twice daily.
When should I take Ketotifene?
You can take Ketotifene once in the morning and once in the evening.
How often can you use Ketotifene?
It is usually instilled in the affected eye(s) twice daily, 8 to 12 hours apart.
How long does Ketotifene take to work?
It can take several weeks for the full effects of this Ketotifene to become apparent (usually within 10 weeks).
How long does Ketotifene stay in my system?
The onset of action of Ketotifene is slow, and it may take 4 to 6 weeks to achieve full prophylactic value under certain conditions.
Does Ketotifene make me sleepy?
This Ketotifene may cause some people to become drowsy, dizzy, or less alert than they are normally.
Does Ketotifene help with anxiety?
Ketotifene can reduce behavioural suppression in rodent models of anxiety and attenuate the behavioural consequences of withdrawal from treatment with drugs of abuse.
What happen If I missed dose of Ketotifene?
If you miss a dose of Ketotifene, 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.
What happen if I overdose on Ketotifene?
Symptoms of overdose may include unusual drowsiness, confusion, hyperexcitability (especially in children), rapid heart rate, dizziness or fainting, seizures, and loss of consciousness.
What should if I overdose on Ketotifene?
An overdose of ketotifen ophthalmic is not expected to be dangerous. Seek emergency medical attention if anyone has accidentally swallowed the medication.
Can Ketotifene affects my heart ?
Ketotifene did not influence these effects of xamoterol on resting haemodynamics.
Can Ketotifene affect my kidneys?
The curative effect of Ketotifene on the kidney markers can be attributed to its antioxidant properties. Treatment with Ketotifene blunted AKI-induced renal dysfunction in rat kidney and reduced oxidative damage.
Can Ketotifene affects my liver?
Ketotifene may be beneficial to screen the patient for liver disease and frequently monitor liver function tests throughout the time of treatment especially in elderly patients.
