Description of the active substance :.
This information is a reference and it is not enough that the drug was prescribed by a doctor. .
Antiallergic agent . Levocetirizine, (R) -enantiomer of cetirizine, is a selective antagonist of peripheral histamine H 1 -receptors. The affinity of levocetirizine (Ki = 3.2 nmol / l) with histamine H 1 -receptors is 2 times higher than that of cetirizine (Ki = 6.3 nmol / l). Studies of pharmacokinetics in healthy volunteers have shown that when applied to the skin and mucous membranes of the nose, the activity of levocetirizine in half the dose is comparable to the activity of cetirizine in a whole dose.
Levocetirizine inhibits the activity of eotaxin-induced transendothelial migration of eosinophils in skin and lung cells. Pharmacodynamic studies demonstrated three main inhibitory effects of levocetirizine at a dose of 5 mg in the first 6 hours after exposure to pollen: suppression of VCAM-1, changes in vascular permeability, and decreased activation of eosinophils. Like cetirizine, the action against histamine-induced skin reactions does not depend on the plasma concentrations of the drug.
Levocetirizine prevents development and facilitates the course of allergic reactions, has an antiexudative, antipruritic effect; practically does not have anticholinergic and antiserotonin action.
Levocetirizine at a dose of 5 mg contributes to suppression of the inflammatory-exudative reaction to histamine to the same extent as cetirizine at a dose of 10 mg.The ECG did not reveal a significant effect of levocetirizine on the QT interval.
After ingestion, levocetirizine is rapidly absorbed from the digestive tract. Food intake does not affect the fullness of absorption, although its speed is reduced. C maxin blood plasma is achieved through 0.9 h after a single oral intake. The equilibrium state is achieved after 2 days. C max after single and repeated (5 mg daily) intake is 270 ng / ml and 308 ng / ml, respectively.
Binding to plasma proteins is 90%. Data on the distribution of the drug in tissues and penetration through the BBB are not available. V d is 0.4 l / kg. Excreted in breast milk.
Less than 14% of the administered dose is metabolized in the liver by oxidation of the aromatic ring, N- and O-dealkylation and conjugation with taurine.Dealkylation is predominantly catalyzed by CYP3A4, and CYP isoforms participate in the oxidation of the aromatic ring. Levocetirizine does not affect the activity of the isoenzymes CYP1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 in concentrations much higher than the peak concentrations with oral administration of 5 mg. Due to insignificant metabolism and lack of metabolic inhibition, the interaction of levocetirizine with other substances is unlikely.
T 1/2 is 7.9 В± 1.9 hours. The total clearance is 0.63 ml / min / kg. Levocetirizine and its metabolite are excreted mainly by the kidneys (85.4% of the dose taken), by glomerular filtration and active tubular secretion. Excretion through the intestine is 12.9%.
The pharmacokinetics of levocetirizine is linear, independent of dose and time, and has small differences in different subjects. The pharmacokinetic profiles of a single enantiomer and cetirizine are similar. At the absorption or excretion there is no chiral inversion.
The total clearance of levocetirizine correlates with QC (this should be taken into account when determining the intervals between doses in patients with moderate or severe renal dysfunction). With anuria, the overall clearance is reduced by approximately 80% compared with healthy subjects. With a standard procedure for 4-hour hemodialysis, less than 10% of levocetirizine is excreted.
Symptomatic treatment of symptoms of year-round and seasonal allergic rhinitis (including persistent allergic rhinitis) and allergic conjunctivitis: sneezing, rhinorrhea, lacrimation, congestion hyperemia; hay fever (hay fever); urticaria (including chronic idiopathic urticaria); other allergic dermatoses, accompanied by itching and rash; angioedema.
Is taken orally, regardless of food intake.
Adults and children over the age of 6 years - 5 mg 1 time / day.
Children aged 2-6 years - 1.25 mg 2 times / day.
The duration of treatment depends on the type, duration and course of the symptoms. For the treatment of hay fever, it takes 3-6 weeks, and with a short-term exposure to pollen, it is usually sufficient to take the drug for 1 week.
From the side of the central nervous system: often - headache, drowsiness, increased fatigue; infrequently, asthenia.
From the digestive system: often - dry mouth; infrequently - abdominal pain; very rarely - nausea, a violation of functional liver tests.
Allergic reactions: very rarely - angioedema, itching, skin rash, hives, anaphylaxis.
Other: very rarely - weight gain, dyspnoea.
Renal failure of severe degree (CC below 10 ml / min); children under 2 years; hypersensitivity to levocetirizine.
PREGNANCY AND LACTATION
Clinical studies of the use of levocetirizine in pregnancy are not available. It is not recommended for use in pregnancy and lactation (breastfeeding).
Older patients with moderate or severe renal dysfunction may need to adjust the dosage regimen.
Patients with impaired renal function require correction of the dosing regimen depending on the CK.
Patients with isolated impairment of liver function do not need any dose changes. Patients with a combined violation of the liver and kidneys are recommended to specify the dose.
Patients should refrain from drinking alcohol during the application of levocetirizine.
Use in Pediatrics
Levocetirizine is used in children over 2 years in a special dosage form.
Impact on the ability to drive vehicles and manage mechanisms
Comparative clinical studies showed no signs of disturbance in the level of wakefulness, reaction time or ability to drive vehicles after taking the recommended doses of levocetirizine. However, some patients may experience drowsiness, fatigue or asthenia during admission. It should be used with caution in patients who manage motor vehicles and engaged in activities that require rapidity of psychomotor reactions.
A decrease in cetirizine clearance (16%) was observed with multiple theophylline injections (400 mg 1 time / day); while the pharmacokinetics of theophylline with simultaneous administration of cetirizine did not change.
In susceptible patients, simultaneous use of levocetirizine and ethanol or other CNS depressant agents can lead to the potentiation of a depressant effect on the CNS.