Cetirizine

treatment of symptoms of year-round and seasonal allergic rhinitis and allergic conjunctivitis (such as itching, sneezing, nose congestion, rhinorea, lacrimation, conjunctiva hypermia);

hay fever (flaymaking) ;

urticaria;

allergic dermatoses, including.h. atopic dermatitis, accompanied by itching and rashes.

Inside.

Children over 6 years old and adults : initial dose - 5 mg (1/2 table. or 10 drops) once a day, if necessary, can be increased to 10 mg (1 table. or 20 drops) 1 time a day. Sometimes the initial dose is 5 mg (1/2 tab. or 10 drops) may be sufficient to achieve a therapeutic effect. Daily dose - 10 mg (1 table. or 20 drops).

Children from 6 to 12 months : 2.5 mg (5 drops) 1 time per day.

Children from 1 year to 2 years : 2.5 mg (5 drops) up to 2 times a day.

Children from 2 to 6 years old : 2.5 mg (5 drops) 2 times a day or 5 mg (10 drops) 1 time a day.

Sick with renal failure, the dose decreases depending on the creatinine clearance: with Cl creatinine 30–49 ml / min - 5 mg 1 time per day, at 10–29 ml / min - 5 mg per day.

Because Cetirizine^® excreted by kidneys, when prescribing the drug, patients with renal failure and elderly patients should be adjusted to the extent of creatinine clearance. Creatinin clearance for men can be calculated based on the concentration of serum creatinine, according to the following formula:

Cl creatinine, ml / min

Creatinine clearance for women can be calculated by multiplying the value obtained by a coefficient of 0.85.

For adult patients with renal and liver failure, dosing is carried out according to the table above.

Children with renal failure are adjusted for creatinine clearance and body weight.

Patients with impaired liver function only do not need to correct the dosing mode.

For all dosage forms

hypersensitivity to cetyrizin, hydroxysine or piperazine derivatives, as well as other components of the drug ;

terminal stage of renal failure (Cl creatinine <10 ml / min)

pregnancy;

period of breastfeeding.

With caution : chronic renal failure (with Cl creatinine> 10 ml / min, metering mode correction is required); old age (cubular filtration can be reduced); epilepsy and patients with increased convulsive readiness; patients with predisposing factors to urinate (see. "Special instructions").

For tablets covered with film shell, additionally:

hereditary unpertruence of galactose, lack of lactase or glucose-galactose malabsorption syndrome ;

childhood up to 6 years.

For drops additionally :

children under 6 months of age (due to the limited data on the effectiveness and safety of drugs).

With caution : childhood up to 1 year.

Possible side effects are given below by body systems and frequency of occurrence: very often (≥1/10); often (≥1/100, <1/10); infrequently (≥1/1000, <1/100); rarely (≥1/10000, <1/1000); very rarely (1/1000).

From the side of the immune system : rarely - hypersensitivity reactions; very rarely - anaphylactic shock.

From the side of the nervous system : often - headache, increased fatigue, dizziness, drowsiness; infrequently - pastezia; rarely - cramps; very rarely - perversion of taste, dyskinesia, dystonia, fainting, tremor, tick; frequency unknown - memory impairment, including.h. amnesia.

Psychiatric disorders : infrequently - excitement; rarely - aggression, confusion of creation, depression, hallucinations, sleep disturbance; frequency unknown - suicidal ideas.

From the side of the body of view : very rarely - impaired accomodality, blurred vision, nystagmus.

From the side of the hearing organ : frequency unknown - vertigo.

From the digestive system : often - dry mouth, nausea; infrequently - diarrhea, abdominal pain.

From the side of the MSS : rarely - tachycardia.

From the respiratory system : often - rhinitis, pharyngitis.

From the metabolic side : rarely - increasing body weight.

From the urinary system : very rarely - dysuria, enuresis; frequency unknown - urine delay.

From the side of laboratory indicators : rarely - a change in functional liver samples (increased activity of liver transaminases, SchF, GGT and bilirubin concentrations); very rarely - thrombocytophenia.

From the side of the skin : infrequently - rash, itching; rarely - urticaria; very rarely - angioneurotic swelling, persistent erythema.

General disorders : infrequently - asthenia, malaise; rarely - peripheral edema; frequency unknown - increase in appetite.

Symptoms (when taking the drug once at a dose of 50 mg): confusion, diarrhea, dizziness, increased fatigue, headache, malaise, medriasis, itching, weakness, anxiety, sedative effect, drowsiness, stupor, tachycardia, tremor, urine delay.

Treatment: immediately after taking the drug - gastric lavage or vomiting induction. The appointment of activated carbon, symptomatic and supportive therapy are recommended. There is no specific antidote. Hemodialysis is ineffective.

• H₁antihistamines

Cetirizine is an active substance of the drug Cetirizine^® - is a metabolite of hydroxysine, belongs to the group of competitive antagonists of histamine and blocks H₁histamine receptors.

Cetirisin warns development and facilitates the course of allergic reactions, and has antitudent and anti-exudative effect. Cetirisin affects the early histone-dependent stage of allergic reactions, limits the release of inflammation mediators at a late stage of an allergic reaction, and also reduces the migration of eosinophiles, neutrophils and basophiles, stabilizes the membranes of fat cells. Reduces the permeability of capillaries, prevents the development of tissue edema, relieves the spasm of smooth muscles. Eliminates the skin reaction to the introduction of histamine, specific allergens, as well as cooling (with cold urticaria). Reduces histin-induced bronchocongricia with bronchial asthma of the light current.

Cetirisin does not have an anti-cholinergic and anti-serotonin effect. In therapeutic doses, the drug has virtually no sedative effect. After taking cetyrizin in a single dose of 10 mg, its action develops after 20 minutes (in 50% of patients), after 60 minutes (in 95% of patients) and lasts more than 24 hours. Against the background of course treatment, tolerance for the antihistamine action of cetyrizin does not develop. After the cancellation of therapy, the effect persists up to 3 days.

The pharmaceutical parameters of cetyrizin change linearly.

Suction. After taking it inside, the drug is quickly and completely absorbed from the LCD. Eating does not affect the completeness of absorption, although its speed decreases. In adults, after a single medication in therapeutic dose C_max in blood plasma is 300 ng / ml and is achieved through (1 ± 0.5) h.

Distribution. Cetirisin on (93 ± 0.3)% binds to blood plasma proteins. V_d is 0.5 l / kg. When taking the drug at a dose of 10 mg for 10 days, cetyrizin cumulation is not observed.

Metabolism. In small quantities, it is metabolized in the body by O-dealkylation (unlike other antagonists H₁-histamines that are metabolized in the liver using a cytochrome system) with the formation of pharmacologically inactive metabolite.

The conclusion. In adults T_1/2 is approximately 10 hours; in children from 6 to 12 years old - 6 hours, from 2 to 6 years old - 5 hours, from 6 months to 2 years old - 3.1 hours. Approximately 2/3 of the accepted dose of the drug is withdrawn by the kidneys unchanged.

In elderly patients and patients with chronic liver diseases with a single medication at a dose of 10 mg T_1/2 increases by about 50%, and system clearance is reduced by 40%.

In patients with renal failure of mild severity (Cl creatinine> 40 ml / min), pharmacokinetic parameters are similar to those in patients with normal kidney function.

In patients with moderate renal failure and in patients undergoing hemodialysis (Cl creatinine <7 ml / min), when taking the drug inward at a dose of 10 mg T_1/2 lengthens 3 times, and the total clearance is reduced by 70% relative to these indicators in patients with normal kidney function, which requires a corresponding change in the dosing mode.

Cetirisin is practically not removed from the body during hemodialysis.

When studying the drug interaction of cetyrizin with pseudoephedrine, cimetidine, ketokonazole, redytromycin, azithromycin, diazepam, glypidine and antipyrin, clinically significant unwanted interactions were not detected.

With simultaneous use with theophylline (400 mg / day), the total clearance of cetyrizin is reduced by 16% (theophylline kinetics does not change).

With simultaneous use with AUC ritonavir, cetyrizin increased by 40%, while the same indicator of the ritonavir slightly changed (−11%).

With simultaneous use with macrolides (azitromycin, red bloodmicin) and ketoconazole, changes to the ECG were not noted.

When using the drug in therapeutic doses, data on the interaction with alcohol were not obtained (at a blood alcohol concentration of 0.5 g / l). Nevertheless, one should refrain from drinking alcohol during therapy with a drug in order to avoid oppression of the central nervous system.

A three-day “laundering” period is recommended before the appointment of allergological samples due to the fact that H₁-histamines blockers inhibit the development of skin allergic reactions.