Pharmacokinetic parameters of cetyrizine at its intake in doses from 5 to 60 mg change linearly.
Tmax in plasma is (1±0.5) h, and Cmax is 300 ng/ml.
Pharmacokinetic parameters such as Cmax in plasma and AUC are homogeneous. Food intake does not affect the completeness of cetyrizine absorption, although its rate is decreasing. The bioavailability of different medicinal forms of cethyrizine is comparable.
Ceticin binds to (93±0,3)% with plasma proteins. Vd is 0.5 l/kg. Ceticisin does not affect warfarin binding to proteins. https://pillintrip.com/medicine/cetirizin-mylan
Ceticizine is not subject to extensive primary metabolism.
The T1/2 is approximately 10 hours.
No accumulation was observed in the daily dose of 10 mg of cetyrizine for 10 days.
Approximately 2/3 of the dose taken is excreted with urine in unchanged form.
Special groups of patients
Older people. In 16 older persons, a single dose of 10 mg T1/2 cetyrisine was 50% higher and the clearance was 40% lower than in non-age persons.
Decrease in cethirisin clearance in elderly patients was probably due to reduced renal function in this category of patients.
Kidney failure. In patients with mild renal failure (creatinine Cl >40 ml/min) pharmacokinetic parameters are similar to those in healthy volunteers with normal renal function.
In patients with moderate renal insufficiency and in patients on hemodialysis (Cl creatinine <7 ml/min), the dose of 10 mg T1/2 of cethirisine orally lengthenes by a factor of 3, and the total clearance decreases by 70% in relatively healthy volunteers with normal night function.
For patients with moderate to severe renal failure, a corresponding change in dosing regimen is required (see “Method of administration and doses”).
Cetirizine is poorly removed from the body during hemodialysis.
Liver failure. In patients with chronic liver diseases (hepatocellular, cholestatic and biliary cirrhosis), a single dose of 10 or 20 mg T1/2 of cethirisine increases by about 50% and the clearance is reduced by 40% compared to healthy subjects. Dose correction is only necessary if a patient with hepatic failure also has concomitant renal failure.
Children. T1/2 in children aged 6 to 12 is 6 hours, 2 to 6 years is 5 hours, 6 months to 2 years is reduced to 3.1 hours.
Use of the substance Cetyrizine
To relieve the nasal and ocular symptoms of year-round (persistent) and seasonal (intermittent) allergic rhinitis and allergic conjunctivitis (itching, sneezing, nasal congestion, rhinorrhoea, lacrimation, conjunctival hyperemia); symptoms of pollinosis (hay fever); symptoms of urticaria (hay fever); allergic rhinitis.including chronic idiopathic), other allergic dermatosis, including allergic dermatitis, accompanied by itching and rashes, in adults and children from 6 months (in the form of drops) or from 6 years of age (in the form of pills).
Use in children from 6 to 12 months is possible only as prescribed by a doctor and under strict medical supervision.
Hypersensitivity to cetyrizine, hydroxysine or any piperazine derivatives; terminal stage of renal failure (Cl creatinine <10 ml/min); age up to 6 months (for the pharmaceutical form of a drop, due to limited data on the efficacy and safety of the application of cetyrizine); age up to 6 years (for the pharmaceutical form of the pill); pregnancy.