Zyrtec, 10 mg 20 pcs

Pharmacological action – anti-allergic, antihistamine.

Pharmacodynamics

Cetirizine – the active ingredient of the drug Zyrtec® is a metabolite of hydroxyzine, belongs to the group of competitive histamine antagonists and blocks H1-histamine receptors.

Cetirizine prevents the development and facilitates the course of allergic reactions, has antipruritic and antiexudative actions. Cetirizine affects the early histamine-dependent stage of allergic reactions, limits the release of inflammatory mediators at the later stage of the allergic reaction, and also reduces migration of eosinophils, neutrophils and basophils and stabilizes mast cell membranes. It reduces capillary permeability, prevents the development of tissue edema, relieves smooth muscle spasm. Eliminates the skin reaction to the introduction of histamine, specific allergens, as well as cooling (in cold urticaria). Reduces histamine-induced bronchoconstriction in mild bronchial asthma.

Cetirizine has no anticholinergic and antiserotonin effects. In therapeutic doses the drug practically does not cause a sedative effect. After a single dose of 10 mg of cetirizine it causes the action in 20 minutes (in 50% of patients), in 60 minutes (in 95% of patients) and lasts more than 24 hours. During a course of treatment, tolerance to the antihistamine effect of cetirizine does not develop. After discontinuation of therapy the effect lasts up to 3 days.

Pharmacokinetics

The pharmacokinetic parameters of cetirizine change linearly.

Intake. After oral administration the drug is quickly and completely absorbed from the gastrointestinal tract. Food intake does not affect the completeness of absorption, although its speed decreases. In adults after a single use of the drug in a therapeutic dose Cmax in plasma is 300 ng/ml and is reached in (1±0.5) hours.

Distribution. Cetirizine is (93±0.3)% bound to plasma proteins. Vd is 0.5 l/kg. No cetirizine cumulation is observed when taking the drug in a dose of 10 mg for 10 days.

Metabolism. In small amounts, it is metabolized in the body by O-dealkylation (unlike other H1-histamine receptor antagonists, which are metabolized in the liver via the cytochrome system) to form a pharmacologically inactive metabolite.

Elimination. In adults, T1/2 is approximately 10 h; in children from 6 to 12 years, 6 h; from 2 to 6 years, 5 h; from 6 months to 2 years, 3.1 h. About 2/3 of the taken dose of the drug is excreted unchanged by the kidneys.

In elderly patients and patients with chronic liver disease in single use of the preparation in dose of 10 mg T1/2 is increased approximately by 50%, and systemic clearance is decreased by 40%.

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

In patients with moderate renal insufficiency and in patients on hemodialysis (creatinine Cl<7 ml/min), when administered orally in dose 10 mg, T1/2 is prolonged by 3 times and total clearance is decreased by 70% compared to these parameters in patients with normal renal function, which requires appropriate change of dosing regimen.

Cetirizine is almost not eliminated from the body by hemodialysis.

Indications

Neurodermitis, Increased lacrimation, Sneezing, Diathesis, Dermatosis, Skin itching, Dermatitis, Allergic conjunctivitis, Allergies, Allergic rhinitis, Atopic dermatitis, Pollinosis, Runny nose (rhinitis), Urticaria

• The treatment of symptoms of year-round and seasonal allergic rhinitis, such as itching, sneezing, rhinorrhea, lacrimation, urticaria, and urticaria. Treatment of symptoms of year-round and seasonal allergic rhinitis and allergic conjunctivitis, such as itching, sneezing, rhinorrhea, lacrimation, conjunctival hyperemia;

• hay fever (pollinosis);

• Hives (including chronic idiopathic urticaria).

• Quincke’s edema;

• other allergic dermatoses (including atopic dermatitis) accompanied by itching and rashes.

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Active ingredient

Cetirizine

Composition

Active ingredient:

Cetirizine dihydrochloride 10 mg.

Auxiliary substances:

microcrystalline cellulose,

lactose monohydrate,

colloidal silicon dioxide,

magnesium stearate;

Opadray Y-1-7000 (hypromellose (E464),

titanium dioxide (E171),

MacroGol 400).

How to take, the dosage

The drug is administered orally.

Adults and children over 6 years of age are prescribed in a dose of 10 mg (1 tablet or 20 drops)/day. Adults, 10 mg once daily; children, 5 mg twice daily or 10 mg once daily. Sometimes the initial dose of 5 mg may be sufficient to achieve therapeutic effect.

In children aged 2 to 6 years, 2.5 mg (5 drops) twice daily or 5 mg (10 drops) once daily.

Children aged 1 to 2 years are prescribed 2.5 mg (5 drops) up to 2 times daily.

Children 6 months to 12 months of age are prescribed 2.5 mg (5 drops) once daily.

In patients with renal insufficiency and in elderly patients, the dose of the drug should be adjusted according to the CK values.

Interaction

In the study of drug interactions of cetirizine with pseudoephedrine, cimetidine, ketoconazole, erythromycin, azithromycin, glipizide and diazepam no clinically significant adverse interaction was found.

Concomitant administration with theophylline (400 mg/day) decreases total clearance of cetirizine by 16% (theophylline kinetics is not changed).

When concomitant administration with macrolides and ketoconazole no ECG changes were observed.

When using the drug in therapeutic doses no data about interaction with alcohol (at blood alcohol concentration – 0.5 g/l) were obtained. Nevertheless, the patient should abstain from alcohol during the therapy to avoid CNS depression.

Special Instructions

In children aged 6 months to 6 years, Zyrtec is prescribed in the dosage form of 10 mg/ml drops for oral administration.

Impact on driving and operating ability

An objective assessment of driving and operating ability has shown reliably no adverse reactions when taking the drug in the recommended dose. But nevertheless, during the period of taking the drug it is advisable to refrain from potentially hazardous activities requiring increased concentration and quick psychomotor reactions.

In case of renal impairment

With caution, the drug should be used in patients with chronic renal failure (moderate or severe) and in elderly patients (due to possible decrease of glomerular filtration).

In case of renal failure, the dose is reduced depending on the CK.

It is contraindicated in terminal renal failure (CK < 10 ml/min).

Periatric use

Perhaps due to decreased glomerular filtration, caution should be exercised when prescribing the drug in elderly patients.

Pediatric use

It is contraindicated in children under 6 years of age (for tablets), in children under 6 months of age (for drops).

Contraindications

• terminal stage of renal failure (CK < 10 ml/min);

• pregnancy;

• Lactation (breastfeeding) period;

• hereditary galactose intolerance, lactase deficiency, or glucose-galactose malabsorption syndrome;

• children under 6 years of age (for tablets);

• children under 6 months of age (for drops);

• hypersensitivity to the ingredients of the drug;

• hypersensitivity to hydroxyzine.

The drug should be used with caution in chronic renal failure (dosage regimen adjustment is required), chronic liver disease, elderly patients (due to possible decrease of glomerular filtration).

Side effects

Blood system disorders: thrombocytopenia.

Nervous system disorders: drowsiness, dizziness, headache, aggression, agitation, confusion, depression, hallucinations, insomnia, tics, seizures, dyskinesia, dystonia, paresthesia, syncope, tremor.

VIight: accommodation disorders, blurred vision, nystagmus.

Cardiovascular system: tachycardia.

Respiratory system: rhinitis, pharyngitis.

Digestive system disorders: dry mouth, nausea, abdominal pain, diarrhea, liver function disorders (increased levels of transaminases, alkaline phosphate, GGT, bilirubin).

Urinary system disorders: urinary disorders, enuresis.

Allergic reactions: itching, rash, urticaria, angioedema, hypersensitivity, up to and including anaphylactic shock.

Metabolic reactions: weight gain.

Others: fatigue, asthenia, malaise, edema.

Side effects develop in very rare cases.

Overdose

Symptoms: if the drug is taken once in a dose over 50 mg, confusion, diarrhea, dizziness, increased fatigue, headache, malaise, mydriasis, itching, weakness, sedation, drowsiness, stupor, tachycardia, tremor, urinary retention may occur.

Treatment: gastric lavage or induced vomiting should be performed immediately after taking the drug. Administration of activated charcoal, symptomatic and supportive therapy are recommended.

There is no specific antidote. Hemodialysis is ineffective.

Similarities

Cetrine, Zodak, Cetirizine, Cetirizine-Teva, Cetirizine drops, Solonex