Zaditen^® (Tablets, Drops) Instructions for Use

ATC Code

R06AX17 (Ketotifen)

Active Substance

Ketotifen (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Mast cell membrane stabilizer. Anti-allergic drug

Pharmacotherapeutic Group

Antiallergic agent – mast cell membrane stabilizer

Pharmacological Action

Antiallergic agent. The mechanism of action is associated with the inhibition of the release of histamine and other mediators from mast cells, the blockade of histamine H₁-receptors, and the inhibition of the enzyme phosphodiesterase, resulting in an increase in the level of cAMP (cyclic adenosine monophosphate) in mast cells.

It suppresses the effects of PAF (platelet-activating factor). It does not relieve attacks of bronchial asthma, but prevents their occurrence and helps to reduce their duration and intensity, and in some cases they disappear completely. It facilitates sputum discharge.

Pharmacokinetics

After oral administration, it is almost completely absorbed from the gastrointestinal tract. Simultaneous food intake does not affect the degree of absorption of ketotifen. It is 50% metabolized during the “first pass” through the liver. C_max in blood plasma is reached within 2-4 hours. Plasma protein binding is 75%.

It is eliminated in two phases. T_1/2 in the initial phase is 3-5 hours, in the terminal phase – 21 hours. It is excreted by the kidneys, 60-70% as metabolites, 1% unchanged.

Indications

Atopic bronchial asthma (as part of complex therapy), allergic rhinitis, conjunctivitis.

ICD codes

Dosage Regimen

Administer orally. Determine the dose and regimen individually based on the patient’s age, clinical situation, and the selected dosage form.

For Zaditen^® Tablets: The standard adult and adolescent dose is 1 mg twice daily. Take with morning and evening meals to improve gastrointestinal tolerance.

For pediatric patients aged 3 years and older, the recommended dose is 1 mg twice daily. Do not use the tablet formulation in children under 3 years of age.

For Zaditen^® Drops: Use for ophthalmic administration only. For adults and children over 12 years of age, instill 1 drop into both eyes twice daily.

Limit the duration of treatment with ophthalmic drops to a maximum of 6 weeks. Do not use the drops in children under 12 years of age unless specifically directed.

Initiate therapy at the recommended starting dose. Do not use for the acute relief of an asthma attack.

Be aware that the full therapeutic effect develops gradually over several weeks of continuous treatment. Continue concomitant anti-asthmatic therapy for at least 2 weeks after starting ketotifen.

Maintain treatment for a minimum of 2 to 3 months to assess efficacy. When discontinuing, taper the dose gradually over 2 to 4 weeks to prevent exacerbation of asthma symptoms.

Adverse Reactions

Infections: infrequently – cystitis.

From the immune system: very rarely – severe skin reactions, erythema multiforme exudativum, Stevens-Johnson syndrome.

From metabolism: rarely – weight gain.

From the psyche: possible (especially at the beginning of treatment) – agitation, irritability, insomnia, anxiety (especially in children), nervousness, increased fatigue, drowsiness.

From the nervous system: infrequently – dizziness, headache; rarely – sedative effect (relaxation, slowed reaction); very rarely – convulsions.

From the digestive system: infrequently – dry mouth, nausea, vomiting, diarrhea.

From the liver and biliary tract: very rarely – increased activity of liver enzymes, hepatitis.

Contraindications

Hypersensitivity to ketotifen; first trimester of pregnancy, breastfeeding period; children under 3 years of age – depending on the dosage form.

With caution second and third trimesters of pregnancy, epilepsy, history of seizures, hepatic insufficiency.

Use in Pregnancy and Lactation

Use is contraindicated in the first trimester of pregnancy. Use in the second and third trimesters of pregnancy is possible only in cases where the intended benefit to the mother outweighs the potential risk to the fetus.

Ketotifen penetrates into breast milk, so if it is necessary to use it during lactation, the issue of stopping breastfeeding should be decided.

Use in Hepatic Impairment

Should be used with caution in patients with hepatic insufficiency.

Pediatric Use

It is possible to use in children according to indications, in age-appropriate recommended doses and dosage forms. It is necessary to strictly follow the instructions in the ketotifen drug instructions regarding contraindications for the use of specific ketotifen dosage forms in children of different ages.

Geriatric Use

It is possible to use in elderly patients according to indications, in recommended doses.

Special Precautions

Ketotifen is not used to relieve an attack of bronchial asthma.

Treatment with ketotifen is carried out for a long time, the therapeutic effect is achieved after several weeks of therapy. The duration of therapy should be at least 2-3 months, especially in patients who did not show an effect in the first weeks. Discontinuation of ketotifen treatment should be gradual, over 2-4 weeks, to avoid the risk of exacerbation of bronchial asthma.

Conducted anti-asthmatic therapy should be continued for at least 2 weeks after starting ketotifen.

When ketotifen and bronchodilators are used simultaneously, the dose of the latter can sometimes be reduced.

Ketotifen lowers the threshold of convulsive activity, so it must be prescribed with particular caution to patients with a history of seizures.

In patients simultaneously taking oral hypoglycemic drugs, the number of platelets in peripheral blood should be monitored.

Effect on ability to drive vehicles and mechanisms

Patients taking Ketotifen should refrain from potentially hazardous activities that require increased attention and rapid psychomotor reactions.

Drug Interactions

With simultaneous use of ketotifen and oral antidiabetic drugs, there is a risk of developing reversible thrombocytopenia.

Ketotifen may enhance the effects of other drugs that depress the central nervous system (sedatives, hypnotics).

Simultaneous use of ketotifen with other antihistamines may lead to mutual enhancement of their effects.

During treatment with ketotifen, alcohol consumption should be avoided, as it enhances the depressant effect of ketotifen on the central nervous system.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.