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Generic Name: Cetirizine Hydrochloride
Class: Second Generation Antihistamines
ATC Class: R06AE07
VA Class: AH105
Chemical Name: [2-[4-[(4-Chlorophenyl)phenylmethyl]-1-piperazinyl] ethoxy]-acetic acid dihydrochloride
Molecular Formula: C21H25ClN2O3•2ClH
CAS Number: 83881-52-1

Introduction

Second generation antihistamine; piperazine-derivative, carboxylic acid metabolite of hydroxyzine.1 2 3 11 12 20

Uses for Zyrtec

Allergic Rhinitis

Self-medication for symptomatic relief of rhinorrhea, sneezing, lacrimation, itching eyes, and/or oronasopharyngeal itching associated with seasonal (e.g., hay fever) allergic rhinitis or other upper respiratory allergies.1 2 3 12 20 25 26 27 42 46 49 62 63 68 69 70 71

Slideshow: OTC Medication Use In Pregnancy: Wise or Worrisome?

Symptomatic relief of perennial (nonseasonal) allergic rhinitis.1

May be used alone or in fixed combination with pseudoephedrine hydrochloride;1 63 69 use fixed-combination preparation only when both antihistamine and nasal decongestant activity are needed concurrently.63

Chronic Idiopathic Urticaria

Self-medication for symptomatic relief of pruritus associated with chronic idiopathic urticaria (e.g., hives);1 2 3 12 20 28 29 46 72 not for prevention of chronic idiopathic urticaria or allergic skin reactions.72

Zyrtec Dosage and Administration

Administration

Oral Administration

Administer orally without regard to food.1 2 3 12 14 20 May adjust time of administration for individual patient requirements.1 3

Oral solution (syrup): Use only the measuring device (i.e., cup) provided by the manufacturer.70 72

Chewable tablets: Administer with or without water.1 71

Fixed-combination cetirizine/pseudoephedrine tablets (e.g., Zyrtec-D): Swallow whole; do not break or chew.63 69

Dosage

Available as cetirizine hydrochloride; dosage expressed in terms of the salt.1

Pediatric Patients

Allergic Rhinitis
Seasonal

Self-medication in children 2 to <6 years of age: 2.5 mg once daily (as oral solution); may increase dosage to a maximum of 5 mg daily, given either as a 5-mg dose once daily or, alternatively, as a 2.5-mg dose every 12 hours.1 70 (See Pediatric Use under Cautions.)

Self-medication in children ≥6 years of age: 5 or 10 mg once daily (as chewable or conventional tablets or oral solution), depending on symptom severity.1 2 3 15 20 22 23 25 68 70 71 In clinical trials, most children ≥12 years of age received an initial dosage of 10 mg daily; no additional benefit observed with 20-mg daily dosage.1

Self-medication in children ≥12 years of age: 5 mg twice daily (every 12 hours) (in fixed combination with 120 mg pseudoephedrine hydrochloride).63 69

Perennial
Oral

Children 6 months to <2 years of age: 2.5 mg once daily (as oral solution).1 In children 12–23 months of age, may increase dosage to a maximum of 5 mg daily, given as 2.5 mg every 12 hours.1 (See Pediatric Use under Cautions.)

Children 2–5 years of age: 2.5 mg once daily (as oral solution);1 may increase dosage to a maximum of 5 mg daily, given either as a 5-mg dose once daily (as chewable tablets or oral solution) or, alternatively, as a 2.5-mg dose every 12 hours (as oral solution).1 (See Pediatric Use under Cautions.)

Children ≥6 years of age: 5 or 10 mg once daily (as chewable or conventional tablets or oral solution), depending on symptom severity.1 2 3 15 20 22 23 25 In clinical trials, most children ≥12 years of age received an initial dosage of 10 mg daily; no additional benefit observed with 20-mg daily dosage.1

Children ≥12 years of age: 5 mg twice daily (every 12 hours) (in fixed combination with 120 mg pseudoephedrine hydrochloride).63

Chronic Idiopathic Urticaria
Oral

Children 6 months to <2 years of age: 2.5 mg once daily (as oral solution).1 In children 12–23 months of age, may increase dosage to a maximum of 5 mg daily, given as 2.5 mg every 12 hours.1 (See Pediatric Use under Cautions.)

Children 2–5 years of age: 2.5 mg once daily (as oral solution);1 may increase dosage to a maximum of 5 mg daily, given either as a 5-mg dose once daily (as chewable tablets or oral solution) or, alternatively, as a 2.5-mg dose every 12 hours (as oral solution).1 (See Pediatric Use under Cautions.)

Self-medication in children ≥6 years of age: 5 or 10 mg once daily (as chewable or conventional tablets or oral solution), depending on symptom severity.1 2 3 15 20 22 23 25 72 In clinical trials, most children ≥12 years of age received an initial dosage of 10 mg daily; no additional benefit observed with 20-mg daily dosage.1

Adults

Allergic Rhinitis
Seasonal
Oral

Self-medication: 5 or 10 mg once daily (as chewable or conventional tablets or oral solution), depending on symptom severity.1 2 3 15 20 22 23 25 68 70 71 In clinical trials, most patients received an initial dosage of 10 mg daily; no additional benefit observed with 20-mg daily dosage.1

Self-medication: 5 mg twice daily (every 12 hours) (in fixed combination with 120 mg pseudoephedrine hydrochloride).63 69

Perennial
Oral

5 or 10 mg once daily (as chewable or conventional tablets or oral solution), depending on symptom severity.1 2 3 15 20 22 23 25 In clinical trials, most patients received an initial dosage of 10 mg daily; no additional benefit observed with 20-mg daily dosage.1

5 mg twice daily (every 12 hours) (in fixed combination with 120 mg pseudoephedrine hydrochloride).63

Chronic Idiopathic Urticaria
Oral

Self-medication: 5 or 10 mg once daily (as chewable or conventional tablets or oral solution), depending on symptom severity.1 2 3 15 20 22 23 25 72 In clinical trials, most patients received an initial dosage of 10 mg daily; no additional benefit observed with 20-mg daily dosage.1

Prescribing Limits

Pediatric Patients

Allergic Rhinitis
Oral

Children 12 months to <2 years of age: Maximum 5 mg daily.1

Self-medication in children 2 to <6 years of age: Maximum 5 mg in 24 hours.70 (See Pediatric Use under Cautions.)

Self-medication in children ≥6 years of age: Maximum 10 mg in 24 hours.68 70 71

Self-medication in children ≥12 years of age: Maximum 10 mg daily (in fixed combination with 120 mg pseudoephedrine hydrochloride).69 Fixed-combination preparation not recommended for children <12 years of age; contains 120 mg pseudoephedrine hydrochloride, which exceeds recommended single dose in such patients.63

Children ≥12 years of age: In clinical trials, a 20-mg daily dosage did not provide additional clinical benefit.1

Chronic Idiopathic Urticaria
Oral

Children 12 months to 5 years of age: Maximum 5 mg daily.1

Self-medication in children ≥6 years of age: Maximum 10 mg in 24 hours.72

Children ≥12 years of age: In clinical trials, a 20-mg daily dosage did not provide additional clinical benefit.1

Adults

Allergic Rhinitis
Oral

Self-medication: Maximum 10 mg in 24 hours (alone or in fixed combination with 120 mg pseudoephedrine hydrochloride).68 69 In clinical trials, a 20-mg daily dosage did not provide additional clinical benefit.1

Chronic Idiopathic Urticaria
Oral

Self-medication: Maximum 10 mg in 24 hours.72 In clinical trials, a 20-mg daily dosage did not provide additional clinical benefit.1

Special Populations

Hepatic Impairment

Children <6 years of age: Use not recommended.1

Adults and children ≥6 years of age: 5 mg once daily (as chewable or conventional tablets or oral solution).1 3

Adults and children ≥12 years of age: 5 mg once daily (in fixed combination with 120 mg pseudoephedrine hydrochloride).63

Renal Impairment

Children <6 years of age: Use not recommended.1

Adults and children ≥6 years of age: 5 mg once daily (as chewable or conventional tablets or oral solution) in patients with impaired renal function (e.g., Clcr of 11–31 mL/minute) or those on hemodialysis (e.g., Clcr <7 mL/minute).1 3

Adults and children ≥12 years of age: 5 mg once daily (in fixed combination with 120 mg pseudoephedrine hydrochloride) in patients with impaired renal function (e.g., Clcr of 11–31 mL/minute) or those on hemodialysis (e.g., Clcr <7 mL/minute).63

Geriatric Patients

Self-medication in patients ≥65 years of age: 5 mg once daily (as chewable or conventional tablets or oral solution); do not exceed this amount in 24 hours.70 71 72

Cautions for Zyrtec

Contraindications

  • Known hypersensitivity to cetirizine, hydroxyzine, or any ingredient in the formulation.1 3 63 68 69 70 71 72

Warnings/Precautions

General Precautions

Prescribing and Dispensing Errors

Ensure accuracy of prescription; similarities in spelling, dosage intervals, and tablet strengths of Zyrtec and Zyprexa (olanzapine, an atypical antipsychotic agent) may result in errors.65

CNS Effects

Risk of somnolence;1 2 3 5 6 27 28 39 41 42 43 49 caution required when performing hazardous activities requiring mental alertness or physical coordination (e.g., operating machinery, driving a motor vehicle).1 3 (See Specific Drugs under Interactions.)

Use of Fixed Combinations

When used in fixed combination with pseudoephedrine hydrochloride (e.g., Zyrtec-D), consider the cautions, precautions, and contraindications associated with pseudoephedrine.63 69

Specific Populations

Pregnancy

Chewable or conventional tablets or oral solution: Category B.1

Fixed-combination cetirizine hydrochloride/pseudoephedrine hydrochloride: Category C.63

Lactation

Distributed into milk.1 63 Use not recommended.1 3 57 63 68 69 70 71 72

Pediatric Use

Chewable or conventional tablets or oral solution: Safety and efficacy not established in children <6 months of age; oral solution is the recommended formulation in children <2 years of age.1

Fixed-combination cetirizine hydrochloride/pseudoephedrine hydrochloride: Safety and efficacy not established in children <12 years of age; use not recommended in this age group.63

Risk of overdosage and toxicity (including death) in children <2 years of age receiving OTC preparations containing antihistamines, cough suppressants, expectorants, and nasal decongestants alone or in combination for relief of symptoms of upper respiratory tract infection.66 67 Clinicians should ask caregivers about use of nonprescription cough and cold preparations to avoid overdosage.

Geriatric Use

Insufficient experience in patients ≥65 years of age to determine whether geriatric patients respond differently than younger adults.1 No overall differences in safety relative to younger patients, but increased sensitivity cannot be ruled out.1

Select dosage with caution because of age-related decreases in renal function; periodic monitoring of renal function recommended.1 3 20 39 46 Dosage adjustment recommended in patients ≥65 years of age.1 (See Geriatric Patients under Dosage and Administration.)

Hepatic Impairment

Decreased clearance in patients with chronic hepatic impairment.1 3 20 39 Dosage adjustment necessary.1 3 (See Hepatic Impairment under Dosage and Administration.)

Use not recommended in children <6 years of age with hepatic impairment.1

Renal Impairment

Decreased clearance in patients with moderate renal impairment (Clcr of 11–31 mL/minute) or in those on hemodialysis.1 3 20 46 60 Dosage adjustment necessary.1 (See Renal Impairment under Dosage and Administration.)

Use not recommended in children <6 years of age with renal impairment.1

Common Adverse Effects

Adults and children ≥12 years of age: Somnolence, fatigue, dry mouth.1 Insomnia reported with cetirizine hydrochloride-pseudoephedrine hydrochloride fixed combination.63

Children 2–11 years of age: Headache, pharyngitis, abdominal pain.1

Children 6 months to 2 years of age: Irritability, fussiness, insomnia, fatigue, malaise.1

Interactions for Zyrtec

Metabolized minimally in the liver.2 May have low potential for adverse drug interactions associated with metabolic enzyme systems.2

Drugs Affecting Hepatic Microsomal Enzymes

Concomitant administration with drugs known to inhibit CYP microsomal enzymes has not been associated with clinically important changes in ECG parameters (e.g., QTc intervals).1 3 31 56

Specific Drugs

Drug

Interaction

Comments

Azithromycin

No clinically important changes in ECG parameters observed with concomitant therapy; no clinically important interactions reported1 3 31 56

CNS depressants (e.g., alcohol, sedatives, tranquilizers)

Possible additive CNS effects (e.g., increased drowsiness)1 3 68 69 70 71 72

Avoid concomitant use1 3

Erythromycin

No clinically important changes in ECG parameters observed with concomitant therapy; no clinically important interactions reported1 3 31 56

Ketoconazole

Prolongation of QTc interval (with an increase of 17.4 msec) observed with concomitant administration; no clinically important interactions reported1 56 57

Not considered clinically important1 56 57

MAO inhibitors

Potentiated pressor effects of sympathomimetic drugs (e.g., pseudoephedrine)63

Avoid concomitant use of fixed-combination preparation containing cetirizine hydrochloride and pseudoephedrine hydrochloride (e.g., Zyrtec-D) with an MAO inhibitor, or for 2 weeks after discontinuance of an MAO inhibitor63

Pseudoephedrine

No pharmacokinetic interactions observed1 3

Theophylline

Decreased clearance (16%) of cetirizine; disposition of theophylline not altered with concomitant administration1 3

Zyrtec Pharmacokinetics

Absorption

Bioavailability

Rapidly absorbed from the GI tract following oral administration,12 14 47 48 with peak plasma concentrations achieved in about 1 hour.1 2 3 4 14 39 46 47 48

Bioavailability of chewable tablets or oral solution is comparable to that of conventional tablets.1

Onset

Antihistaminic effect noted in 95% of adults and children at 1 hour.1 2 3 6 14 20 43 57

Duration

Antihistaminic effect persists for about 24 hours.1 2 3 6 14 20 43

Food

Food may decrease peak plasma concentrations and rate of absorption, but does not affect extent of absorption.1 2 3 12 20 63

Distribution

Extent

Distribution into human body tissues not fully elucidated.1 3 Appears to be extensively distributed into many body tissues and fluids in animals; 3 brain cetirizine concentrations were <10% of those measured in plasma.2

Distributed into milk.1

Plasma Protein Binding

Approximately 93%.1 3

Elimination

Metabolism

Undergoes a low degree of first-pass metabolism in the liver; metabolized to limited extent by oxidative O-dealkylation to a metabolite with negligible antihistaminic activity.1 2 3 11 14 39 46 47 56 57

Elimination Route

80% of a dose is excreted in urine, mainly as unchanged drug.1 2 4 12 14 20 39 46 47 48 57

Half-life

Initial distribution half-life is about 3 hours;48 terminal elimination half-life is about 8.3 hours.1 2 4 12 14 20 39 47 48 57

Special Populations

In patients with chronic hepatic impairment or moderate renal impairment (e.g., Clcr of 11–31 mL/minute) or in those on hemodialysis, half-life is increased and clearance is decreased.1 3 20 39

In geriatric patients (mean: 77 years of age), half-life is increased and clearance is decreased,1 possibly due to age-related changes in renal function.1 3 20 39 46

In pediatric patients, half-life is decreased and clearance is increased.1

Stability

Storage

Oral

Tablets and Chewable Tablets

20–25°C (may be exposed to 15–30°C).1 63 68 71 72

Solution

20–25°C (may be exposed to 15–30°C).1 Also may be refrigerated at 2–8°C.1

Actions

  • Exhibits selective antagonism of peripheral histamine H1-receptors.1 2 3 6 14 20 47 48

  • Antihistaminic effect is comparable to that of astemizole (no longer commercially available in the US), clemastine, chlorpheniramine, diphenhydramine, hydroxyzine, loratadine, pyrilamine, and terfenadine (no longer commercially available in the US).2 3 20 43 Tolerance to antihistaminic effect usually does not occur.2

  • No appreciable anticholinergic or antiserotonergic effects in animal models,56 57 but dry mouth more common with cetirizine than placebo in clinical trials.1 3 20 28 41 49

Advice to Patients

  • For self-medication, importance of taking only as directed and not exceeding recommended dosage.69

  • Risk of somnolence;1 2 3 5 6 27 28 39 41 42 43 49 importance of exercising caution when performing activities requiring mental alertness or physical coordination (e.g., operating machinery, driving a motor vehicle).1 68 69 70 71 72

  • For self-medication with cetirizine in fixed combination with pseudoephedrine, importance of discontinuing therapy and contacting a clinician if symptoms do not improve within 7 days or are accompanied by fever, or if nervousness, dizziness, or sleeplessness occurs.69

  • For self-medication for management of chronic idiopathic urticaria (e.g., hives), importance of understanding that cetirizine does not prevent hives.72 Importance of consulting a clinician before initiating therapy if hives are unusual in color, look bruised or blistered, or do not itch.72 Importance of discontinuing therapy and contacting a clinician if symptoms do not improve within 3 days or if hives have persisted for >6 weeks.72

  • Importance of understanding that chronic idiopathic urticaria may present with other severe allergic reactions, including anaphylactic shock (e.g., trouble swallowing, swelling of the tongue, trouble speaking, wheezing or trouble breathing, dizziness or loss of consciousness, swelling in or around the mouth, drooling).72 These manifestations may occur when hives first appear or up to several hours later and can be life-threatening if not treated immediately.72 Importance of immediately seeking emergency help if anaphylactic shock occurs.72 If an epinephrine auto-injector has been prescribed, importance of carrying this device at all times; never use cetirizine as a substitute for the epinephrine auto-injector.72

  • Importance of discontinuing the drug immediately and informing a clinician if an allergic or hypersensitivity reaction occurs.69 70 71

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses.1 63

  • Importance of patients with renal or hepatic impairment, heart disease, hypertension, thyroid disease, diabetes mellitus, glaucoma, or difficulty in urination resulting from prostate enlargement not undertaking self-medication without first consulting a clinician.69 70 71 72

  • Importance of women informing their clinician if they are or plan to become pregnant or plan to breast-feed.1 63

  • Importance of informing patients of other important precautionary information. (See Cautions.)

Preparations

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

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Cetirizine Hydrochloride

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Capsules, liquid-filled

10 mg*

Cetirizine Hydrochloride Capsules

Zyrtec Liquid Gels

McNeil

Solution

5 mg/5 mL*

Cetirizine Hydrochloride Oral Solution

Children’s Zyrtec Allergy Syrup

McNeil

Children’s Zyrtec Perfect Measure

McNeil

Tablets

5 mg*

Cetirizine Hydrochloride Tablets

10 mg*

Cetirizine Hydrochloride Tablets

Tablets, chewable

5 mg*

Cetirizine Hydrochloride Chewable Tablets

Children’s Zyrtec Chewables

McNeil

10 mg*

Cetirizine Hydrochloride Chewable Tablets

Children’s Zyrtec Chewables

McNeil

Tablets, film-coated

5 mg*

Cetirizine Hydrochloride Tablets

10 mg*

Cetirizine Hydrochloride Tablets

Zyrtec

McNeil

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Cetirizine Hydrochloride Combinations

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Oral

Tablets, extended-release

5 mg with Pseudoephedrine Hydrochloride 120 mg*

Cetirizine Hydrochloride and Pseudoephedrine Hydrochloride Tablets

Zyrtec-D

McNeil

Comparative Pricing

This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 02/2014. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.

Cetirizin-Pseudoephedrine 5-120MG 12-hr Tablets (PERRIGO PHARMACEUTICALS): 24/$23.99 or 48/$36.97

Cetirizine HCl 10MG Tablets (PERRIGO): 100/$18.99 or 300/$39.96

Cetirizine HCl 5MG Tablets (APOTEX): 100/$99.99 or 300/$253.98

Cetirizine HCl Childrens Alrgy 1MG/ML Syrup (PERRIGO PHARMACEUTICALS): 118/$15.99 or 236/$20.97

Cetirizine-Pseudoephedrine 5-120MG 12-hr Tablets (SANDOZ): 24/$36.99 or 48/$65.97

ZyrTEC-D Allergy & Congestion 5-120MG 12-hr Tablets (MCNEIL CONSUMER): 12/$22.99 or 36/$42.97

AHFS DI Essentials. © Copyright, 2004-2014, Selected Revisions February 1, 2012. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

References

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38. Lambert D, Hantzperg M, Danglas P et al. Double-blind comparative study of terfenadine and cetirizine in chronic idiopathic urticaria. Allerg Immunol. 1993; 25:235- 40.

39. Simons FER, Watson WTA, Minuk GY et al. Cetirizine pharmacokinetics and pharmacodynamics in primary biliary cirrhosis. J Clin Pharmacol. 1993; 33:949-54. [IDIS 320880] [PubMed 7693767]

40. Wasserfallen JB, Leuenberger P, Pécoud A. Effect of cetirizine, a new H1 antihistamine, on the early and late allergic reactions in a bronchial provocation test with allergen. J Allergy Clin Immunol. 1993; 91:1189-97. [IDIS 315943] [PubMed 8099593]

41. Berkowitz RB, Dockhorn R, Lockey R et al. Comparison of efficacy, safety, and skin test inhibition of cetirizine and astemizole. Ann Allergy Asthma Immunol. 1996; 76:363- 8. [IDIS 363440] [PubMed 8612120]

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