Description
Ketotifen Pharmacodynamics
Ketotifen belongs to the group of cycloheptathiophenones and has a pronounced antihistamine effect. It does not belong to the bronchodilator antiasthmatic agents
The mechanism of action is associated with inhibition of release of histamine and other mediators from mast cells, blockade of histamine H1-receptors and inhibition of phosphodiesterase enzyme, as a result of which the level of cAMP (cyclic adenosine monophosphate) in mast cells increases. Suppresses the effects of PAF (platelet-activating factor). Does not stop asthmatic attacks, but prevents their occurrence and leads to a reduction in their duration and intensity, and in some cases they disappear completely. Facilitates expectoration of sputum.
Indications
Atopic bronchial asthma (as part of complex therapy), allergic rhinitis, conjunctivitis.
Contraindications
– Hypersensitivity to the active substance or any of the excipients of the drug;
– I trimester of pregnancy, breast-feeding:
– Children under 3 years of age (for this dosage form)
With caution:
II and III trimesters of pregnancy, epilepsy, seizure episodes in history, hepatic insufficiency.
Pregnancy and lactation:
The drug is contraindicated in I trimester of pregnancy. In II and III trimesters of pregnancy ketotifen should be used with caution and only in case when possible benefit for mother exceeds potential risk for fetus.
If it is necessary to use ketotifen during lactation, breastfeeding should be stopped.
Dosage and administration
- Orally, with a meal, with water.
- Adults: 1 tablet (1 mg) 2 times a day, morning and evening. For patients with significant sedative effects, a slow increase in dose during the first week is recommended, starting with 0.5 mg in the evening before bedtime, until the therapeutic dose is gradually reached. If necessary, the daily dose may be increased to 4 mg – 2 tablets 2 times a day.
- At a higher dose, a more rapid onset of therapeutic effect can be expected.
- Children over 3 years of age: 1 tablet (1 mg) 2 times a day, morning and evening, with meals.
- Administration in elderly patients
No dose adjustment is required for elderly patients - Duration of treatment
Treatment is prolonged; therapeutic effect is achieved after several weeks of therapy. - Treatment should be continued for at least 2-3 months, especially in patients who had no effect during the first weeks. Treatment with ketotifen should be discontinued gradually over 2-4 weeks to avoid the risk of bronchial asthma exacerbation.
