Zyrtec (cetirizine hydrochloride) is a second-generation antihistamine indicated for the management of seasonal and perennial allergic rhinitis, as well as chronic idiopathic urticaria. As a selective H1-receptor antagonist, it works by blocking histamine, a key chemical mediator responsible for allergic symptoms. Its non-sedating profile and rapid onset of action make it a preferred choice among healthcare professionals for providing consistent, 24-hour relief with a single daily dose. This product card provides a comprehensive overview of its pharmacological profile, clinical applications, and essential safety information.

Features

• Active Ingredient: Cetirizine hydrochloride 10 mg (tablets) or 5 mg/5 mL (syrup)
• Formulation: Film-coated tablets and clear, banana-grape flavored syrup
• Pharmacological Class: Piperazine-derivative, second-generation antihistamine
• Onset of Action: Approximately 1 hour post-administration
• Duration of Effect: Up to 24 hours
• Prescription Status: Over-the-counter (OTC) in most markets
• Excipients: Microcrystalline cellulose, lactose, magnesium stearate, and others (see packaging)

Benefits

• Provides rapid and long-lasting relief from sneezing, rhinorrhea, nasal pruritus, and ocular symptoms associated with allergic rhinitis
• Effectively reduces wheals and pruritus in patients with chronic spontaneous urticaria
• Demonstrates a favorable side effect profile with minimal sedative effects compared to first-generation antihistamines
• Offers convenient once-daily dosing, enhancing patient adherence and consistency in symptom control
• Suitable for use in adults and children aged 2 years and older, with appropriate dose adjustments
• Does not require hepatic metabolism via cytochrome P450 system, reducing potential for certain drug interactions

Common use

Zyrtec is primarily indicated for the relief of symptoms associated with:

• Seasonal allergic rhinitis (hay fever), including sneezing, rhinorrhea, pruritus of the nose/throat/palate, and lacrimation
• Perennial allergic rhinitis caused by indoor allergens such as dust mites, pet dander, or mold
• Chronic idiopathic urticaria (hives of unknown origin), reducing the number and size of wheals and relieving associated itching

Dosage and direction

Adults and children 6 years and older: 10 mg (1 tablet or 2 teaspoons [10 mL] of syrup) once daily. May be taken with or without food. Children 2 to 5 years: 2.5 mg (½ tablet or 1 teaspoon [5 mL] of syrup) once daily. Dose may be increased to a maximum of 5 mg daily, given as 2.5 mg every 12 hours. Geriatric patients: No dose adjustment necessary in patients with normal renal function. Renal impairment (creatinine clearance 11–31 mL/min): 5 mg once daily. Hepatic impairment: Dose adjustment not necessary unless accompanied by renal impairment. Tablets should be swallowed whole with water. Do not crush or chew.

Precautions

• Use with caution in patients with renal impairment (dose adjustment required)
• May cause drowsiness in some patients; assess individual response before operating machinery or driving
• Contains lactose; not suitable for patients with galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption
• Syrup formulation contains sorbitol; caution in patients with hereditary fructose intolerance
• Not recommended during pregnancy unless clearly needed (Category B)
• Use during lactation only if potential benefit justifies potential risk (cetirizine is excreted in breast milk)
• In elderly patients, monitor for potential anticholinergic effects such as dry mouth, constipation, or urinary retention

Contraindications

• Hypersensitivity to cetirizine, hydroxyzine, or any component of the formulation
• Severe renal impairment (creatinine clearance ≤10 mL/min)
• Children under 2 years of age (safety and efficacy not established)
• Concomitant use with alcohol or other CNS depressants (increases risk of sedation)

Possible side effect

Most common adverse reactions (≥2%) include:

• Somnolence (14%)
• Fatigue (6%)
• Dry mouth (5%)
• Pharyngitis (2%)
• Dizziness (2%)

Less common reactions (<2%) include:

• Headache, nausea, abdominal pain
• Diarrhea, epistaxis
• Agitation, paradoxical excitation (particularly in children)
• Allergic reactions including rash, pruritus, urticaria, angioedema
• Tachycardia, palpitations
• Increased liver enzymes (transient)

Drug interaction

• Alcohol: Enhanced sedative effect; avoid concomitant use
• CNS depressants (benzodiazepines, opioids, barbiturates): Additive CNS depression
• Theophylline: May slightly decrease cetirizine clearance (not clinically significant)
• No clinically significant interactions with warfarin, azithromycin, ketoconazole, or cimetidine observed in studies
• Use caution with other anticholinergic drugs due to potential additive effects

Missed dose

If a dose is missed, take it as soon as remembered. If it is near the time of the next dose, skip the missed dose and resume the regular dosing schedule. Do not double the dose to catch up.

Overdose

Symptoms may include drowsiness, restlessness, irritability, and in severe cases, tachycardia and urinary retention. In case of suspected overdose, seek immediate medical attention. Treatment is symptomatic and supportive. Gastric lavage may be considered if administered soon after ingestion. Cetirizine is not effectively removed by hemodialysis.

Storage

Store at room temperature (15–30°C or 59–86°F). Protect from moisture and light. Keep bottle tightly closed. Store syrup formulation upright. Keep out of reach of children. Do not use after expiration date printed on packaging.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional before starting any new medication, especially if you have pre-existing medical conditions or are taking other medications. Read and follow all label instructions carefully. The manufacturer is not liable for any adverse effects resulting from improper use or self-diagnosis.

Reviews

Clinical studies demonstrate Zyrtec’s efficacy: In a randomized, double-blind trial of 186 patients with seasonal allergic rhinitis, cetirizine 10 mg once daily provided significant improvement in total symptom scores compared to placebo (p<0.001). Another study involving 188 patients with chronic urticaria showed 73% of cetirizine-treated patients experienced complete or marked relief versus 37% with placebo. Real-world evidence from post-marketing surveillance confirms its favorable benefit-risk profile, with high patient satisfaction rates regarding symptom control and convenience of once-daily dosing.