Asfen
Asfen Uses, Dosage, Side Effects, Food Interaction and all others data.
Asfen is a potent anti-allergic substance possessing a powerful and sustained non-competitive histamine (H1) receptor blocking property. Asfen inhibits the release of mediators (e.g histamine, leukotrienes and prostaglandins) from cells responsible for type-(I) allergic reactions. Asfen 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.
Asfen 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 | Asfen |
| 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 |
| Weight | 1 mg/5ml, 1mg/5ml, 1mg |
| Type | Syrup, Tablet |
| 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 | Virgo Pharmaceuticals Ltd, Remington Pharmaceutical Industries (pvt) Ltd, |
| Available Country | Bangladesh, Pakistan |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Asfen is used for the prophylactic treatment of bronchial asthma, symptomatic treatment of allergic conditions including rhinitis and conjunctivitis.
Asfen 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. Asfen possesses marked anti-anaphylactic properties and is effective in preventing asthmatic attack. Asfen exerts sustained inhibitory effect on histamine reactions, which can be clearly dissociated from its antianaphylactic properties. Experimental investigations in asthmatic subjects have shown that Asfen is as effective orally as administered by inhalation as a selective mast cell stabiliser. Antihistamines were ineffective in those tests. The effectiveness of Asfen 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 Asfen may take several weeks to become fully established. Asfen will not abort established attacks of asthma.
Asfen 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.
Asfen is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Asthma, Allergic, Eye pruritus, Seasonal Allergic Conjunctivitis
How Asfen works
The precise mechanism(s) through which ketotifen exerts its therapeutic effects are unclear. Asfen 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
Asfen 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 Asfen 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, Asfen treatment must be supplemented by specific antimicrobial therapy. During the first day of treatment with Asfen, reactions may be impaired and patients should be warned not to take charge of vehicle or machinery until the effect of Asfen treatment on the individual is known. Patient should be advised to avoid alcoholic drinks. Asfen may potentiate the effects of sedatives, hypnotic, antihistamines and alcohol.
The formulation of Asfen 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 Asfen concomitantly with oral antidiabetics and it has been suggested that this combination should therefore be avoided. Since Asfen has the properties of the antihistamines, it may potentiate the effects of other CNS depressant drugs such as alcohol, antihistamines, hypnotics and sedatives.
If Asfen 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
Asfen 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, Asfen in pregnancy and lactation is not recommended.
Contraindication
A reversible fall in the platelet count has been observed in a few patients receiving Asfen concomitantly with oral antidiabetic agent and it has been suggested that this combination should therefore be avoided.
Hypersensitivity to Asfen 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 Asfen 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 Asfen.
Storage Condition
Store at 25° C.
Innovators Monograph
You find simplified version here Asfen
Asfen contains Ketotifen see full prescribing information from innovator Asfen Monograph, Asfen MSDS, Asfen FDA label
FAQ
What is Asfen used for?
Asfen ophthalmic (eye) solution is used to temporarily prevent itching of the eye caused by a condition known as allergic conjunctivitis. Asfen is also used to help prevent asthma attacks.
How safe is Asfen?
Asfen 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 Asfen work?
Asfen works by preventing inflammation and allergic reactions in your body.
What are the common side effects of Asfen?
The common side effects of Asfen 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 Asfen safe during pregnancy?
Animal data reveal no harmful effects of Asfen during pregnancy.No adequate and well-controlled studies of Asfen in pregnant women have been performed.
Is Asfen safe during breastfeeding?
Because absorption from the eye is limited, Asfen would not be expected to cause any adverse effects in breastfed infants after maternal use of ketotifen eye drops.
Can I drink alcohol with Asfen?
Asfen it is best not to drink alcohol while you are on Asfen. 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 Asfen for a long time?
Asfen may be taken with or without food.
How much can I take Asfen 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 Asfen?
You can take Asfen once in the morning and once in the evening.
How often can you use Asfen?
It is usually instilled in the affected eye(s) twice daily, 8 to 12 hours apart.
How long does Asfen take to work?
It can take several weeks for the full effects of this Asfen to become apparent (usually within 10 weeks).
How long does Asfen stay in my system?
The onset of action of Asfen is slow, and it may take 4 to 6 weeks to achieve full prophylactic value under certain conditions.
Does Asfen make me sleepy?
This Asfen may cause some people to become drowsy, dizzy, or less alert than they are normally.
Does Asfen help with anxiety?
Asfen 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 Asfen?
If you miss a dose of Asfen, 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 Asfen?
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 Asfen?
An overdose of ketotifen ophthalmic is not expected to be dangerous. Seek emergency medical attention if anyone has accidentally swallowed the medication.
Can Asfen affects my heart ?
Asfen did not influence these effects of xamoterol on resting haemodynamics.
Can Asfen affect my kidneys?
The curative effect of Asfen on the kidney markers can be attributed to its antioxidant properties. Treatment with Asfen blunted AKI-induced renal dysfunction in rat kidney and reduced oxidative damage.
Can Asfen affects my liver?
Asfen 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.
