Colfen

Yellow coloured, oblong shape tablets with score line on both sides.
Each tablet contains Cetirizine Dihydrochloride 10 mg.

Pharmacology: Mechanism of Action: Cetirizine is an antihistamine as its principal effects are mediated via selective inhibition of peripheral H1 receptors.
Pharmacokinetics: Cetirizine is rapidly absorbed from the gastrointestinal tract after oral administration, peak plasma concentrations being attained in about 1 hour. It is highly bound to plasma proteins and has an elimination half-life of about 11 hours. Cetirizine has been detected in breast milk. It is excreted primarily in the urine mainly as unchanged drug.

Adults and children of 6 years or above: symptomatic treatment of seasonal rhinitis, perennial allergic rhinitis and urticaria of allergic origin.

For oral administration only.
The tablets need to be swallowed with a glass of liquid.
Adults: 10 mg once daily. A 5 mg starting dose may be proposed if this leads to satisfactory control of the symptoms.
Children: Children over 12 years of age: 10 mg once daily.
Children aged from 6 to 12 Years: 5 mg twice daily.
Elderly: Data do not suggest that the dose needs to be reduced in elderly subjects provided that the renal function is normal.
Patients with moderate to severe renal impairment: Since cetirizine is mainly excreted via renal route, in cases no alternative treatment can be used, the dosing intervals must be individualised according to renal function. Refer to the following table and adjust the dose as indicated. (See equation.)

Click on icon to see table/diagram/image

Dosing adjustments for adult patients with impaired renal function: See table.

Click on icon to see table/diagram/image

In paediatric patients suffering from renal impairment, the dose will have to be adjusted on an individual basis taking into account the renal clearance, age and body weight of the patient.
Patients with hepatic impairment: No dose adjustment is needed in patients with solely hepatic impairment.
Patients with hepatic impairment and renal impairment: Dose adjustment is recommended (see Patients with renal impairment as previously mentioned).

In initial observation, overdosage of Cetirizine may cause restlessness and irritability, followed by drowsiness. Should overdose occur, treatment should be symptomatic or supportive, taking into account any concomitantly ingested medications. In the case of massive overdosage, gastric lavage should be performed as soon as possible. Usual supportive measures should be provided and routine observation carried out regularly.

Contraindicated in those patients with known hypersensitivity to any of its ingredients. Cetirizine should not be administered to pregnant women during the first 3 month of pregnancy and women who are breastfeeding.

Activities Requiring Mental Alertness: In clinical trials, the occurrence of somnolence has been reported in some patients taking cetirizine; due caution should therefore be exercised when driving car or operating potentially dangerous machinery. Concurrent use of cetirizine with alcohol or other CNS depressants should be avoided because additional reductions in alertness and additional impairment of CNS performance may occur.
Carcinogenesis, Mutagenesis, and Impairment of Fertility: In a 2 years carcinogenicity study in rats, cetirizine was not carcinogenic at dietary doses up to 20 mg/kg. In a 2 years carcinogenicity study in mice, cetirizine caused an increased incidence of benign liver tumors in males at a dietary dose of 16 mg/kg. No increase in the incidence of liver tumors was observed in mice at a dietary dose of 4 mg/kg. The clinical significance of these findings during long-term use of cetirizine is not known. Cetirizine was not mutagenic in the Ames test, and not clastogenic in the human lymphocyte assay, the mouse lymphoma assay, and in vivo micronucleus test in rats. In a fertility and general reproductive performance study in mice, cetirizine did not impair fertility at an oral dose of 64 mg/kg.
Pediatric Under 2 Years Old: The safety and effectiveness of cetirizine in pediatric patients under the age of 2 years have not yet been established.
Pregnancy and Lactation: Safe uses of cetirizine during pregnancy and lactation have not been established, therefore it is not recommended.
Effects on ability to drive and use machine: Objective measurements of driving ability, sleep latency and assembly line performance have not demonstrated any clinically relevant effects at the recommended dose of 10 mg. However, patients who experience somnolence should refrain from driving, engaging in potentially hazardous activities or operating machinery. Patients intending to drive, engaging in potentially hazardous activities or operating machinery should not exceed the recommended dose and should take their response to the medicinal product into account.

There have been occasional reports of mild and transient subjective side-effects such as, headache, dizziness, drowsiness, agitation, dry mouth and gastrointestinal discomfort. In objective tests of psychomotor function, the incidence of sedation with cetirizine was similar to that of placebo. Occasionally symptoms of hypersensitivity have been reported.

To date there are no known interactions with other drugs. Nevertheless, Colfen Allergy Tablet should be used with caution if sedatives are also being taken.

Store below 30°C. Protect from light.

Antihistamines & Antiallergics

R06AE07 - cetirizine ; Belongs to the class of piperazine derivatives used as systemic antihistamines.

C