Cetirizine (EENT) (Monograph)

Brand name: Zerviate
Drug class: Antiallergic Agents
Chemical name: [2-[4-[(4-Chlorophenyl)phenylmethyl]-1-piperazinyl] ethoxy]-acetic acid dihydrochloride
Molecular formula: C₂₁H₂₅Cl_lN₂O₃•2ClH
CAS number: 83881-52-1

Introduction

Cetirizine hydrochloride is a histamine H₁-receptor antagonist.

Uses for Cetirizine (EENT)

Cetirizine hydrochloride has the following uses:

Cetirizine hydrochloride ophthalmic solution (cetirizine 0.24%) is indicated for treatment of ocular itching associated with allergic conjunctivitis.

Cetirizine (EENT) Dosage and Administration

General

Cetirizine hydrochloride is available in the following dosage form(s) and strength(s):

Sterile ophthalmic solution: 2.4 mg of cetirizine per mL (0.24%).

Dosage

It is essential that the manufacturer's labeling be consulted for more detailed information on dosage and administration of this drug. Dosage summary:

Pediatric Patients

The recommended dosage of cetirizine hydrochloride ophthalmic solution (cetirizine 0.24%) is one drop instilled in each affected eye twice daily (approximately 8 hours apart).

Adults

The recommended dosage of cetirizine hydrochloride ophthalmic solution (cetirizine 0.24%) is one drop instilled in each affected eye twice daily (approximately 8 hours apart).

Cautions for Cetirizine (EENT)

Contraindications

None.

Warnings/Precautions

Contamination of Tip and Solution

As with any eye drop, care should be taken not to touch the eyelids or surrounding areas with the dropper tip of the bottle to prevent contaminating the tip and solution. Keep the bottle closed when not in use.

Contact Lens Wear

Patients should be advised not to wear a contact lens if their eye is red.

Cetirizine hydrochloride should not be instilled while wearing contact lenses. Remove contact lenses prior to instillation of cetirizine hydrochloride. The preservative in cetirizine hydrochloride, benzalkonium chloride, may be absorbed by soft contact lenses. Lenses may be reinserted after 10 minutes following administration of cetirizine hydrochloride.

Specific Populations

Pregnancy

Risk Summary: There were no adequate or well-controlled studies with cetirizine hydrochloride ophthalmic solution (cetirizine 0.24%) in pregnant women. Cetirizine should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus.

Animal Data: Cetirizine was not teratogenic in mice, rats, or rabbits at oral doses up to 96, 225, and 135 mg/kg, respectively (approximately 1300, 4930, and 7400 times the maximum recommended human ophthalmic dose, on a mg/m ² basis).

Lactation

Cetirizine has been reported to be excreted in human breast milk following oral administration. Multiple doses of oral cetirizine (10 mg tablets once daily for 10 days) resulted in systemic levels (mean C _max= 311 ng/mL) that were 100 times higher than the observed human exposure (mean C _max= 3.1 ng/mL) following twice-daily administration of cetirizine ophthalmic solution 0.24% to both eyes for one week. Comparable bioavailability has been found between the tablet and syrup dosage forms. However, it is not known whether the systemic absorption resulting from topical ocular administration of cetirizine hydrochloride could produce detectable quantities in human breast milk.

There is no adequate information regarding the effects of cetirizine on breastfed infants, or the effects on milk production to inform risk of cetirizine hydrochloride to an infant during lactation. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for cetirizine hydrochloride and any potential adverse effects on the breastfed child from cetirizine hydrochloride.

Pediatric Use

The safety and effectiveness of cetirizine hydrochloride has been established in pediatric patients two years of age and older. Use of cetirizine hydrochloride in these pediatric patients is supported by evidence from adequate and well-controlled studies of cetirizine hydrochloride in pediatric and adult patients.

Geriatric Use

No overall differences in safety or effectiveness have been observed between elderly and younger patients.

Common Adverse Effects

The most common adverse reactions (1–7%) were ocular hyperemia, instillation site pain, and visual acuity reduced.

Drug Interactions

Specific Drugs

It is essential that the manufacturer's labeling be consulted for more detailed information on interactions with this drug, including possible dosage adjustments. Interaction highlights:

Please see product labeling for drug interaction information.

Actions

Mechanism Of Action

Cetirizine hydrochloride is a histamine H₁-receptor antagonist (antihistamine) and an inhibitor of release of histamine from mast cells. Its effects are mediated via selective inhibition of H₁ histamine receptors. The antihistaminic activity of cetirizine has been documented in a variety of animal and human models. In vivo and ex vivo animal models have shown negligible anticholinergic and antiserotonergic activity. In vitro receptor binding studies have shown no measurable affinity for other than H₁ receptors.

Advice to Patients

Patient Counseling Information

Risk of Contamination: Advise patients not to touch dropper tip to eyelids or surrounding areas, as this may contaminate the dropper tip and ophthalmic solution. Advise patients to keep the bottle closed when not in use.

Concomitant Use of Contact Lenses: Advise patients not to wear contact lenses if their eyes are red. Advise patients that cetirizine hydrochloride should not be used to treat contact lens-related irritation. Advise patients to remove contact lenses prior to instillation of cetirizine hydrochloride. The preservative in cetirizine hydrochloride solution, benzalkonium chloride, may be absorbed by soft contact lenses. Lenses may be reinserted ten minutes following administration of cetirizine hydrochloride.

Additional Information

AHFSfirstRelease^™. For additional information until a more detailed monograph is developed and published, the manufacturer's labeling should be consulted. It is essential that the manufacturer's labeling be consulted for more detailed information on usual uses, dosage and administration, cautions, precautions, contraindications, potential drug interactions, laboratory test interferences, and acute toxicity.

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.