Cetirizine

The reviewed prescription solution covers perennial allergic rhinitis at age 6–23 months and chronic idiopathic urticaria at age 6 months–5 years. FDA describes seasonal-allergy approval from age 2 and perennial-allergy/chronic-hive approval from 6 months across oral products. Reviewed OTC allergy products relieve sneezing, rhinorrhea and itchy eyes/nose/throat; their self-care directions begin at age 2 for appropriate low-dose liquids/chewables or age 6 for 10 mg products. Do not infer infant OTC self-treatment.

Quzyttir treats acute urticaria in adults and children at least 6 months old; it is a supervised IV product. Zerviate treats ocular itching from allergic conjunctivitis, with pediatric safety/effectiveness established from age 2. These routes do not use the oral solution schedule.

For the reviewed 1 mg/mL solution, dosing may be taken without regard to food. The following are Drug Facts self-care directions; organ disease and age limits require clinician advice.

For the reviewed prescription solution: age 6–11 months, 2.5 mg (2.5 mL) once daily for perennial rhinitis or chronic urticaria; age 12–23 months may increase to 2.5 mg every 12 hours, maximum 5 mg/day. Age 2–5 years with chronic urticaria starts at 2.5 mg once daily and may increase to 5 mg once daily or 2.5 mg every 12 hours. Use clinician supervision; trial mg/kg exposures are not the recommended dosing table.

Reviewed 10 mg tablets, liquid-filled capsules, ODTs and 10 mg chewables use one daily dose from age 6, maximum 10 mg/day, with a 5 mg product potentially appropriate for milder symptoms. Those 10 mg packages direct adults ≥65 and children <6 to a clinician. Chew/crush chewables fully before swallowing; ODTs melt in the mouth. The separately reviewed 2.5 mg chewable permits age 2–<6 dosing of one daily, increasing to two daily or one every 12 hours if needed, maximum 5 mg/day. Do not choose tablet count without checking its strength.

Administer as an IV push over 1–2 minutes, once every 24 hours as needed for acute urticaria. Its 10 mg/mL solution requires accurate small-volume measurement. For pretreatment of an infusion product, follow that infusion product’s prescribing instructions.

Instill one drop in each affected eye twice daily, approximately 8 hours apart. Use the opened single-use container immediately for one or both eyes, then discard remaining solution. Do not touch its tip to the eye/skin. Remove contacts first; reinsert after 10 minutes and avoid contacts in a red eye.

Oral cetirizine is contraindicated with known cetirizine, ingredient or hydroxyzine hypersensitivity. Quzyttir also explicitly contraindicates levocetirizine hypersensitivity. Zerviate’s current label lists no formal contraindications; its eye-specific precautions still apply.

The reviewed oral, IV and ophthalmic labels have no boxed warning. That does not remove sedation risk, hypersensitivity precautions or the FDA warning about severe itching after long-term oral use is stopped.

Systemic use can cause somnolence, fatigue, dry mouth and dizziness; younger children may have irritability or insomnia. Quzyttir studies also reported dyspepsia, taste change, feeling hot, headache and presyncope at low frequency. Zerviate trials reported eye redness, instillation pain and reduced visual acuity. Serious postmarketing oral reports include anaphylaxis, liver injury, seizures, severe skin reactions and withdrawal pruritus; reports do not establish incidence.

Alcohol and CNS depressants may further impair alertness with systemic cetirizine. Review sedatives/tranquilizers before use. Oral interaction studies found no clinically important interaction with several tested antibiotics or low-dose theophylline, but theophylline 400 mg reduced cetirizine clearance modestly; larger doses may have greater effects. Do not infer that all combinations are interaction-free.

Check for cetirizine in more than one product and distinguish cetirizine alone from pseudoephedrine-containing combination products. This page does not provide the combination’s dosing or decongestant safety rules. OTC allergy formulations share the same active drug despite different brands and strengths.

Current reviewed OTC oral products require clinician dose selection for kidney or liver disease; they do not supply a numerical adjustment chart. Oral PK studies summarized in the current Quzyttir label show prolonged elimination with CrCl 11–31 mL/min and dialysis, and with chronic liver disease. Quzyttir itself requires no adjustment for renal/hepatic impairment in eligible patients, with monitoring for antihistamine effects, but is not recommended below age 6 with either impairment. Ophthalmic labeling supplies no organ-adjustment schedule.

Prescription oral and IV data start at 6 months; younger-infant safety/effectiveness is not established. Match each pediatric regimen to its indication. Ophthalmic approval/data begin at age 2. For older adults, review renal function and sedation susceptibility; the OTC liquid’s 5 mg/day direction differs from 10 mg tablet/capsule packages that advise clinician input.

OTC labels advise consulting a health professional before pregnancy use. Current IV/ophthalmic labels have insufficient controlled human pregnancy evidence; animal studies did not show teratogenicity at the studied high oral exposures. Make a patient-specific decision about route and benefit/risk rather than declaring universal pregnancy safety.

The OTC Drug Facts say breastfeeding use is not recommended; LactMed’s September 2025 assessment considers occasional small oral doses acceptable and cetirizine an acceptable antihistamine option when needed. Larger/prolonged doses may sedate an infant or reduce milk supply, particularly early in lactation or with pseudoephedrine. Reconcile that evidence with maternal need and infant monitoring through a clinician. Eye-drop exposure is much lower; pressing the tear duct for at least a minute and wiping excess reduces systemic absorption.

Cetirizine is a hydroxyzine metabolite acting mainly at peripheral H1 receptors. Oral peak concentrations occur around 1 hour; protein binding is about 93% and adult elimination half-life about 8.3 hours. Metabolism is limited, with substantial urinary recovery as unchanged drug. Food delays the peak without materially changing total exposure.

Adult oral half-life

About 8.3 hours

Protein binding

About 93%

IV administration produces a higher peak than oral dosing even when overall exposure is similar; that distinction supports supervised dosing. Ophthalmic administration produces much lower systemic concentrations than oral 10 mg treatment. Neither comparison permits exchanging route-specific milligram doses.

Check symptom relief, alertness, concurrent medicines and kidney/liver status when relevant. Confirm liquid concentration and measure in mL with the supplied/calibrated device. Review duration before months of daily oral use and discuss the withdrawal-itching warning. New severe itching warrants clinician assessment rather than a self-designed taper. Follow route-specific eye and IV instructions.

Contact poison control or emergency care for excess dosing, significant sedation, agitation or other concerning symptoms. Management is supportive; there is no specific cetirizine antidote, and dialysis does not effectively remove it. Do not use tolerance of a previous dose as justification to exceed the package maximum.

Padagis prescription oral solution is 1 mg/mL, banana-grape flavored, colorless to slightly yellow; 120 mL bottle NDC 45802-626-26. Current Quzyttir uses 1 mL of 10 mg/mL solution in a single-use 2 mL-size amber vial. Current Zerviate supplies 0.2 mL single-use containers, carton of 30, NDC 82667-015-24.

Reviewed oral products include 1 mg/mL solution, 2.5 mg and 10 mg chewables, 10 mg tablets, 10 mg ODTs and 10 mg liquid-filled capsules. Other manufacturers may offer additional strengths; use the actual package. Quzyttir is IV cetirizine HCl 10 mg/mL. Zerviate is 0.24% cetirizine ophthalmic solution, equivalent to approximately 0.29% hydrochloride; oral and IV solutions are not eye drops.

Reviewed OTC oral products store at 20–25°C; ODTs avoid high humidity and capsules also avoid excessive heat/light. The reviewed prescription solution permits 20–25°C with 15–30°C excursions or refrigeration at 2–8°C. Quzyttir stores at 20–25°C with 15–30°C excursions; discard unused contents. Zerviate stores at 15–25°C in its foil pouch until use; discard an opened unit after dosing. Follow the actual product seal and storage instructions.