Hydroxyzine Dosage blocks H1-histamine receptors, has anti-muscarinic and sedative effect, contributes to the suppression of some subcortical zones.
In addition to H1-histaminoblocking, has a bronchodilating and anti-emetic effect, has a moderate inhibitory effect on gastric secretion. Hydroxysin significantly reduces itching in patients with hives, eczema and dermatitis. Improves cognitive functions, including attention and memory. Does not cause addiction, mental dependence and withdrawal syndrome with prolonged use. In liver failure H1-histaminoblocking effect can be prolonged up to 96 hours after a single use.
Possesses moderate anxiolytic activity.
Polysomnography in patients with insomnia and anxiety demonstrates prolonged sleep duration, reduced frequency of night awakenings after a single or repeated use of hydroxysine in a dose of 50 mg. Decrease in muscle tension in patients with anxiety was noted when taken in a dose of 50 mg 3 times a day.
H1-histaminoblocking effect occurs approximately 1 h after ingestion. The sedative effect appears 30-45 min. later.
Suction. After ingestion the absorption is high, the Tmax value is 2 hours. After taking an average dose of 50 mg Cmax in adults - 70 ng / ml. After ingestion of a single dose of 50 mg Cmax is 65 ng/ml.
Distribution. Hydroxyzine Contraindications is more concentrated in tissues than in plasma. The Vd value is 7-16 l/kg in adults. Hydroxysine penetrates the GHB and placenta, concentrating more in the fetal than in the maternal tissues.
Hydroxyzine penetrates well into the skin, with concentrations of hydroxysin in the skin much higher than those in serum, both after single and repeated use. Plasma concentrations of hydroxysin do not necessarily reflect its binding to tissues or its distribution in the skin. Metabolism. Hydroxysine is metabolized in the liver. Cetyrizine, the main metabolite (45%), is a blocker of H1-histamine receptors. Metabolites are found in breast milk.