Each film-coated tablet contains: Cetirizine dihydrochloride 10 mg.
A white or almost white powder. Freely soluble in water, practically insoluble in acetone and dichloromethane. A 5 % solution in water has a pH of 1.2 to 1.8.
Pharmacology: Cetirizine hydrochloride, a piperazine derivative and metabolite of hydroxyzine is described as a non-sedating antihistamine which is long-acting and has some mast-cell stabilizing activity. It appears to have a low potential for drowsiness in usual doses and to be virtually free of antimuscarinic activity.
Pharmacokinetics: Cetirizine is rapidly absorbed from the gastrointestinal tract after oral administration, peak plasma concentrations being attained within about one hour. Food delays the time to peak plasma concentrations but does not decrease the amount of drug absorbed. It is highly bound to plasma proteins and has an elimination half-life of about 10 hours. Cetirizine has been detected in breast milk. Cetirizine is excreted primarily in the urine mainly as unchanged drug. Cetirizine does not appear to cross the blood-brain barrier to a significant extent.
It is used for the symptomatic relief of allergic conditions including rhinitis and chronic urticaria.
In adults and children of 6 years and over, cetirizine hydrochloride is given by mouth in a dose of 10 mg once daily or 5 mg twice daily. In children aged 2 to 6 years old a dose of 5 mg once daily or 2.5 mg twice daily may be used for seasonal allergic rhinitis.
In patients with renal impairment it is recommended that the dosage is reduced to half the usual daily dose. Or as prescribed by the physician.
Patients with a history of hypersensitivity to any constituents of cetirizine.
Drowsiness is a major problem with the sedating antihistamines and those affected should not drive or operate machinery; alcohol should be avoided. Because of their antimuscarinic actions the sedating antihistamines should be used with care in conditions such as angle-closure glaucoma, urinary retention, prostatic hyperplasia, or pyloroduodenal obstruction; antimuscarinic side effects are not a significant problem with the non-sedating antihistamines. Antihistamines should not be given to neonates owing to their susceptibility to antimuscarinic effects.
The most common side-effect of sedating antihistamines is CNS depression, with effects varying from slight drowsiness to deep sleep, and including lassitude, dizziness, and in coordination. These sedative effects, when they occur, may diminish after a few days of treatment.
Sedating antihistamines may enhance the sedative effects of CNS depressants including alcohol, barbiturates, hypnotics, opioid analgesics, anxiolytic sedatives, and antipsychotics. Sedative interactions apply to a lesser extent with the non-sedating antihistamines; they do not appear to potentiate the effects of alcohol, but it should be avoided in excess. Sedating antihistamines have an additive antimuscarinic action with other antimuscarinic drugs, such as atropine and antidepressants (both tricyclics and MAOIs). Potentially hazardous ventricular arrhythmias have occurred when the non-sedating antihistamines astemizole and terfenadine have been given concomitantly with drugs liable to interfere with their hepatic metabolism, with other potentially arrhythmogenic drugs including those that prolong the QT interval, or with those likely to cause electrolyte imbalance.
Store at temperatures not exceeding 30°C.
R06AE07 - cetirizine ; Belongs to the class of piperazine derivatives used as systemic antihistamines.
FC tab 10 mg x 10's, 50's.