Cetirizine10 mg

Cetirizine is a second-generation (non-sedating) antihistamine used for the following indications:

Established / FDA-approved uses

• Relief of symptoms of seasonal and perennial allergic rhinitis, including sneezing, rhinorrhea, nasal and ocular pruritus, and lacrimation.
• Treatment of uncomplicated skin manifestations of chronic idiopathic urticaria, including relief of pruritus and reduction in the number and size of hives/wheals.

Other guideline-supported uses

• Symptomatic relief of allergic conjunctivitis and other allergic skin conditions (e.g., atopic dermatitis-related pruritus), as an adjunct to primary therapy.

Cetirizine does not cure the underlying allergic condition; it controls symptoms while the allergen exposure or condition is otherwise managed.

Each dosage unit of Cetirizine Hydrochloride [Oral] contains cetirizine hydrochloride as the active ingredient, commonly available as:

• Tablets: 10 mg cetirizine hydrochloride (chewable and film-coated forms available).
• Oral syrup/solution: 5 mg cetirizine hydrochloride per 5 mL.

Excipients vary by manufacturer and formulation.

Cetirizine is a potent, selective, second-generation H1-receptor antagonist derived from hydroxyzine. It is widely used for the symptomatic relief of allergic rhinitis and chronic idiopathic urticaria because it has a relatively low potential for sedation and anticholinergic side effects compared with first-generation antihistamines, while still providing effective, once-daily symptom control.

Cetirizine belongs to the class of second-generation (minimally sedating) antihistamines, specifically selective peripheral H1-receptor antagonists.

Cetirizine Hydrochloride [Oral] is a selective antagonist at peripheral histamine H1-receptors. By blocking H1-receptors on vascular endothelium, smooth muscle, and sensory nerve endings, it inhibits histamine-mediated vasodilation, increased vascular permeability, and pruritus, thereby reducing the symptoms of allergic rhinitis and urticaria.

Compared with first-generation antihistamines, Cetirizine Hydrochloride [Oral] crosses the blood-brain barrier to a much lesser extent, which accounts for its lower (though not absent) sedative effect. It has minimal anticholinergic activity. Onset of action is generally within 20-60 minutes, with effects lasting approximately 24 hours, supporting once-daily dosing.

Cetirizine tablets may be taken with or without food, swallowed whole with a glass of water, generally in the evening if once-daily dosing is preferred (to minimize any daytime drowsiness), though it may be taken at any consistent time of day. Oral syrup should be measured using an accurate dosing device, not a household spoon.

Cetirizine has relatively few clinically significant drug interactions compared with first-generation antihistamines, but the following are well recognized:

• CNS depressants (alcohol, sedatives, tranquilizers, opioids, benzodiazepines): concurrent use may cause additive sedation and impaired psychomotor performance; caution advised, especially before driving or operating machinery.
• Theophylline: high-dose theophylline may modestly decrease clearance of Cetirizine, occasionally increasing sedation risk.
• Ritonavir and other agents that inhibit renal or hepatic clearance: may increase plasma concentrations of Cetirizine, warranting dose caution in patients with reduced organ function.

Cetirizine is generally well tolerated. Reported adverse effects include:

Common

• Somnolence/drowsiness (more common than with fexofenadine or loratadine, though less than first-generation antihistamines)
• Headache
• Dry mouth
• Fatigue
• Pharyngitis (in children)
• Dizziness

Less common / rare but clinically important

• Hypersensitivity reactions, including urticaria and angioedema
• Rare hepatic transaminase elevations
• Rare movement disorders or worsening of tics in children

Patients should seek immediate medical attention for signs of a serious allergic reaction (see Contraindications).

Pregnancy: Cetirizine should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; a physician should always be consulted before use in pregnancy. Human data have not shown a clear pattern of fetal harm, and among antihistamines, second-generation agents such as Cetirizine are generally preferred over first-generation antihistamines when treatment is required during pregnancy, but this should still be individualized by a physician.

Lactation: Cetirizine is excreted into human breast milk. Use during breastfeeding is not generally recommended unless a physician determines the benefit outweighs the potential risk (e.g., sedation) to the nursing infant. Consult a physician before use while breastfeeding.

The following precautions apply to Cetirizine:

• Sedation: although classified as minimally sedating, Cetirizine can cause drowsiness in some patients, especially at higher doses; caution is advised when driving or operating machinery until individual response is known.
• CNS depressant use: concurrent alcohol or other CNS depressants may increase sedation (see Interactions).
• Renal/hepatic impairment: dose reduction is required (see Dosage and Administration).
• Elderly patients: may be more susceptible to sedation and anticholinergic-type effects; use the lowest effective dose.
• Seizure disorders: use with caution, as antihistamines may theoretically lower seizure threshold in susceptible individuals.
• Cetirizine is not an antibiotic and has no role in treating bacterial infections.

Overdose of Cetirizine may cause somnolence in adults, and paradoxical agitation or restlessness followed by drowsiness in children. There is no specific antidote. If overdose is suspected, seek immediate medical attention or contact a poison control center right away; treatment is generally supportive and symptomatic. Do not attempt home treatment of a suspected overdose.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Pediatric patients: approved for use down to 6 months of age for allergic rhinitis/urticaria symptom relief under medical guidance at reduced doses; safety and efficacy in infants under 6 months have not been established (see Pediatric Uses).

Elderly: generally well tolerated, but a lower starting dose may be considered, particularly with renal impairment (see Precautions and Warnings).

Renal impairment: dose reduction required; see Dosage and Administration.

Hepatic impairment: dose reduction required; see Dosage and Administration.

For seasonal allergic rhinitis, Cetirizine is typically used for the duration of allergen exposure/symptom period. For perennial allergic rhinitis or chronic idiopathic urticaria, it may be used for longer-term, continuous symptom control under physician supervision, with periodic reassessment of ongoing need.

Second-generation (non-sedating/minimally sedating) antihistamines; selective H1-receptor antagonists.

Cetirizine Hydrochloride [Oral] selectively and competitively blocks peripheral histamine H1-receptors, preventing histamine from binding and triggering the vasodilation, increased capillary permeability, and sensory nerve stimulation (itching, sneezing) that produce allergic symptoms. Its limited penetration of the blood-brain barrier reduces central H1-receptor blockade, resulting in less sedation than first-generation antihistamines while maintaining strong peripheral antihistaminic activity.

B

Cetirizine is approved for use in children as young as 6 months for allergy symptom relief, with dosing adjusted by age:

• Ages 6–23 months: low-dose use (e.g., 2.5 mg once daily) only under direct physician guidance.
• Ages 2–5 years: 2.5 mg once daily, may be titrated up to a maximum of 5 mg/day under medical supervision.
• Ages 6–11 years: 5–10 mg once daily depending on severity.
• Ages 12 years and older: dosed as adults (10 mg once daily).

Safety and efficacy of Cetirizine in infants under 6 months of age have not been established. Children may be more prone to paradoxical excitability with overdose; caregivers should use only pediatric-labeled formulations and accurate measuring devices.