Generic
Cetirizine Hydrochloride
5 brands available in the market
At a glance
Cetirizine Hydrochloride is a potent antihistamine used for the relief of symptoms associated with seasonal and perennial allergic rhinitis and chronic idiopathic urticaria.
Description
Cetirizine Hydrochloride is a potent H1 receptor antagonist that inhibits the histamine-mediated early phase of allergic reactions and reduces inflammatory cell migration. It has no significant anticholinergic and antiserotonergic effects. Cetirizine is effective for allergic rhinitis, chronic idiopathic urticaria, and allergen-induced asthma.
Indications
Allergic rhinitis (seasonal and perennial) symptoms (sneezing, rhinorrhea, itchy/red eyes), uncomplicated skin manifestations of chronic idiopathic urticaria, allergen-induced asthma.
Therapeutic class
Sedating Antihistamine
Pharmacological class
Sedating Antihistamine
Pharmacology
Cetirizine Hydrochloride is a potent H1 receptor antagonist that inhibits the histamine-mediated early phase of allergic reactions and reduces the migration of inflammatory cells and the release of mediators associated with the late phase of allergic reactions. At pharmacologically active doses, it causes almost no drowsiness and does not cause behavioral changes. Food does not affect the extent of absorption but may slightly reduce the rate. Plasma half-life is approximately 11 hours.
Mechanism of action
Cetirizine competitively blocks peripheral H1 histamine receptors, preventing histamine from binding and triggering allergic symptoms. Histamine is a chemical released during allergic reactions that contributes to symptoms like itching, swelling, and mucus production. By inhibiting the action of histamine, cetirizine helps alleviate common allergy symptoms such as sneezing, runny nose, and itchy eyes.
Dosage
Oral Dosage:
- Adults and children ≥6 years: 1 tablet or 2 teaspoonfuls daily (or 1 teaspoonful twice daily)
- Children 2-6 years: 1 teaspoonful once daily or 1/2 teaspoonful twice daily
- Children 6 months-2 years: 1/2 teaspoonful once daily (12-23 months: up to 1/2 teaspoonful every 12 hours)
IV Injection (acute urticaria):
- Adults and adolescents ≥12 years: 10 mg IV push (over 1-2 minutes)
- Children 6-11 years: 5-10 mg IV push
- Children 6 months-5 years: 2.5 mg IV push
Administration
Oral: Can be taken with or without food. IV Injection: Administer as an intravenous push over 1-2 minutes for acute urticaria as directed by a physician.
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not double the dose.
Side effects
Most common side effect: Somnolence (drowsiness)
Other side effects: Headache, dry mouth, dizziness, fatigue.
Precautions & warnings
Caution should be exercised when driving or operating heavy machinery due to potential drowsiness. Alcohol or other CNS depressants may increase drowsiness.
Contraindications
Hypersensitivity to Cetirizine or hydroxyzine.
Drug interactions
No clinically significant drug interactions found with: Theophylline, Azithromycin, Pseudoephedrine, Ketoconazole, Erythromycin.
Food interactions
Food does not affect the overall extent of absorption, though it may slightly reduce the rate.
Use in pregnancy
Pregnancy Category: B. No adequate and well-controlled studies in pregnant women. Use only if clearly needed.
Pregnancy Category: B — always consult a doctor before taking during pregnancy.
Use in lactation
Cetirizine Hydrochloride is excreted in human milk. Use with caution.
Pediatric use
6 months-5 years: Safety and efficacy have been demonstrated.
≥6 years: Adult dosage applies.
Geriatric use
Clearance of cetirizine is reduced in elderly patients in proportion to the decrease in creatinine clearance.
Renal / hepatic impairment
Hepatic and renal impairment: Total body clearance is reduced and AUC/half-life is increased by 2-3 fold in mild-to-moderate hepatic and renal impairment. Dose adjustment may be needed.
Dialysis: Plasma levels are unaffected by hemodialysis. Half-life in dialysis patients is approximately 20 hours.
Overdose effects
Overdose may result in significant somnolence. Manage with standard supportive measures and gastric decontamination if necessary.
Storage conditions
Store in a dry place away from light and heat. Keep out of reach of children.
Chemical structure
Cetirizine Hydrochloride