Elcet, 5 mg 7 pcs.

Pharmacotherapeutic group

H1-histamine receptor blocker (anti-allergic agent).

The ATX code: R06AE09

Pharmacological properties

Pharmacodynamics

Levocetirizine, the active ingredient of Elcet, is the R-enantiomer of cetirizine, a potent and selective histamine antagonist that blocks H]-histamine receptors.

Levocetirizine influences the histamine-dependent stage of allergic reactions and also reduces migration of eosinophils, decreases vascular permeability and limits the release of inflammatory mediators.

Levocetirizine prevents the development and facilitates allergic reactions, has antiexudative and antipruritic effects, it has practically no anticholinergic and antiserotonin action. In therapeutic doses it has practically no sedative effect.

Pharmacokinetics

The pharmacokinetic parameters of levocetirizine change linearly.

Eabsorption.

The drug is quickly and completely absorbed from the gastrointestinal tract after oral administration. Food intake does not affect the completeness of absorption, although it reduces its rate. The maximum concentration (Stah) in blood plasma is reached after 0.9 hour and is 270 ng/ml, the equilibrium concentration is reached after 2 days.

Distribution

Levocetirizine is 90% bound to plasma proteins. The volume of distribution (Vd) is 0.4 l/kg. Bioavailability reaches 100%.

Metabolism

In small amounts (< 14%) it is metabolized in the body by N- and O-dealkylation (unlike other H|-histamine receptor antagonists, which are metabolized in the liver by the cytochrome system) to form a pharmacologically inactive metabolite. Due to insignificant metabolism and lack of metabolic potential, interaction of levocetirizine with drugs seems unlikely.

The elimination half-life (Tx) in adults is 7.9 ± 1.9 hours. In young children the half-life is shorter. In adults, the total clearance is 0.63 ml/min/kg. About 85.4% of the drug dose taken is excreted unchanged by kidneys via glomerular filtration and tubular secretion; about 12.9% – via intestine. Certain groups of patients

Patients with renal failure

In patients with renal failure with creatinine clearance less than 40 ml/min, the drug clearance is decreased. In patients on hemodialysis total clearance is reduced by 80%. Less than 10% of the drug is removed during a standard 4-hour hemodialysis procedure.

Children

The data from a study of the pharmacokinetics of the drug in 14 children aged 6 to 11 years with a body weight between 20 and 40 kg when 5 mg of levocetirizine was taken orally once showed that the Stache and area under the curve (AUC) were about twice that of healthy adults in a cross-match control.

The mean Stache was 450 ng/mL, the maximum concentration was reached after an average of 1.2 hours, total clearance with body weight was 30% higher, and the elimination half-life was 24% shorter in children than in adults.

A retrospective pharmacokinetic analysis was performed in 324 patients (181 children aged 1 to 5 years, 18 children aged 6 to 11 years, and 124 adults aged 18 to 55 years) who received one or more doses of levocetirizine between 1.25 mg and 30 mg. The data obtained in the analysis showed that administration of the drug in a dose of 1.25 mg in children aged 6 months to 5 years resulted in plasma concentrations corresponding to those in adults when the drug was taken once daily.

Elderly patients

There are limited data on pharmacokinetics in elderly patients. When 30 mg of levocetirizine was repeatedly administered once daily for 6 days in 9 elderly patients (age 65 to 74 years), total clearance was approximately 33% lower than that of younger adults.

The distribution of cetirizine racemate has been shown to be more dependent on renal function than on age. This statement may also be applicable to levocetirizine, since both levocetirizine and cetirizine are primarily excreted with the urine. Therefore, in elderly patients, the dose of levocetirizine should be adjusted depending on renal function.